BIOL 1306 Final Review

Distinguish between hypothesis and predictions in the scientific method

A hypothesis is a proposed idea/explanation for a natural phenomenon that is based on previous observations or experimental studies.

A useful hypothesis must make predictions.

Predictions are expected outcomes based on a hypothesis that can be shown to be correct or incorrect through observation or experimentation.

Compare and contrast the different types of chemical bonds and define the terms chemical bond, covalent bond (including polar and nonpolar), ionic bond, and hydrogen bond

Chemical Bond - the force that holds two atoms together.

Covalent Bond - a type of chemical bond in which two atoms share one or more pairs of electrons (usually formed by atoms with similar electronegativities).

Polar - 2 non-metal atoms with different electronegativities, electrons are not shared equally.

Non-Polar - 2 non-metal atoms with the same electronegativities, equally shared electrons.

Ionic Bond - A chemical bond that is formed when an electron is completely transferred from one atom to another (usually formed between a metal and nonmetal).

Hydrogen Bond - A weak interaction between 2 molecules resulting from the attraction between a hydrogen bond and another atom (not considered a bond, more of an attraction between hydrogen ions and an electronegative ion).

From strongest to weakest (Ionic, Covalent, Hydrogen Bonding)

Other Reference:

Chemical bond: the attraction between two atoms, resulting from a sharing of outer shell electrons or the presence of opposite charges on the atoms. The bonded atoms gain complete outer electron shells

Covalent bond: sharing a pair of valence electrons by two atoms

Nonpolar covalent bond: electrons are shared equally because the two atoms have the same electronegativity

Polar covalent bond: when a atom is bonded to a more electronegative atom, the electrons are not shared equally

Ionic bond: Chemical bond resulting from the attraction between oppositely charged ions

Hydrogen bond: type of weak chemical bond that is formed when the slightly positive hydrogen atom of a polar covalent bond in one molecule is attracted to the slightly negative atom of a polar covalent bond in another molecule or in another region of the same molecule

Identify which properties of water are due to hydrogen bonds and explain how

Strong Surface Tension - due to the cohesion of water, more tightly packed on top and more attracted to each other than the surrounding air, the ability of a water strider to walk on water.

High Specific Heat - The amount of heat required to change the temperature of the water is high > higher than alcohol. Hydrogen bonds contribute to water's high specific heat because heat must be absorbed to break hydrogen bonds, since water is made up of lots of hydrogen bonds it takes a lot more energy/ heat to break

those bonds.

Nearly universal solvent properties - solvent = dissolving agent; solution = homogeneous mixture of two

substances; solute = the substance being dissolved. Water is a fine solvent because it is polar and can easily

bond with other molecules.

High heat of vaporization - quantity of heat a liquid must absorb for one gram of it to be converted from the

liquid to a gaseous state.

Cohesion - attraction of water with other water molecules.

Adhesion - attraction of water molecules to other substances.

Explain why water is considered polar

Water is considered a polar solvent because they have -OH and H+ ions and since these ions are charged that makes water a polar solvent.

The unequal sharing of electrons between the atoms and the unsymmetrical shape of the molecule means that a water molecule has two poles - a positive charge on the hydrogen pole (side) and a negative charge on the oxygen pole (side).

Define the terms hydrophilic and hydrophobic and state which correctly describes ions, polar, and nonpolar molecules

Hydrophilic - typically, polar compounds and ionic substances containing partially or fully charged atoms.

Hydrophobic - typically, non-polar molecules and non-ionic (cannot form hydrogen bonds)

Describe and identify the structure of functional groups, including hydroxyl, carbonyl, carboxyl, amino, sulfhydryl, and phosphate in molecular diagrams

Hydroxyl: OH

Carbonyl: C = O

Carboxyl: C = O

\

OH

Amino: H - N

\

N

Sulfhydryl: SH

Phosphate: O

_ ||

O - P = O

||

O

Describe the properties of each functional group and the significance of those properties

- Hydroxyl

- Carbonyl

- Carboxyl

- Phosphate

- Sulfhydryl

- Amino

Hydroxyl: Polar, forms H bonds, -OH

Carbonyl: polar, acidic

Carboxyl: acts as an acid

Phosphate: strong potential to react with water and release energy

Sulfhydryl: can form disulfide bridges

Amino: acts as a base

Identify the type of macromolecule based on a structural diagram

See Diagrams

Compare the structure and function of different types of lipids: triglycerides, phospholipids, steroids, and saturated and unsaturated fatty acids

For Structures see Diagrams

Functions:

triglycerides - One glycerol molecule bonded to three fatty acid molecules. Bonded through condensation (a.k.a dehydration) reaction, releasing H2O molecule. The circled part in the picture (bond between the -OH group and the acid part of the fatty acid is a covalent bond called ester linkage). Note: the Ester Linkage forms from the bonding of the hydroxide from the carboxyl group of a fatty acid and a hydroxyl group on glycerol. The end-result is an ester link, which is a single-bonded C-O connecting the glycerol to the fatty acid and a double-bonded C-O (refer to right picture above).

phospholipids :Join to create phospholipid bilayer (major component of cell membrane). Help transfer biological signals across the cell membrane, they form a barrier between the cell and exterior

steroids: metabolic regulation, reproductive functions, stress responses, behavior, cognition, and mood.

saturated/unsaturated fatty acids: It is easier to pass through an unsaturated fatty acid, than a saturated fatty acid.

Differentiate among primary, secondary, tertiary, and quaternary protein structure, and identify the types of bonds contributing to each

Primary - sequence of a chain of amino acids. Covalent bond called peptide bonds (sequence of amino acids).

Secondary - hydrogen bonding of the peptide backbone causes the amino acids to fold into a repeating patter. Hydrogen bonds (alpha helix or beta pleated sheets)

Tertiary - three-dimensional folding pattern of a protein due to side chain interactions. Hydrogen bonds, ionic bonds, sulfide bridges, Van Der Waals (globular 3D structure) + hydrophobic interactions

Quaternary - protein consisting of more than one amino acid chain. Hydrogen bonds, ionic, Van Der Waals, and covalent bonds, Disulfide bridges (two or more polypeptides)

Compare and contrast the structures of prokaryotic versus eukaryotic cells

Prokaryotic Cells:

- contain organelles

- tiny cells (only 1-10 um in diameter)

- has cell membrane, cell wall, ribosomes, cytoskeleton, and 1 chromosome (circular)

- 1 - 100 plasmids (small circular pieces of DNA containing a few genes)

- contain internal membranes: in-folding of plasma membrane which contain chlorophyll and photosystem proteins.

Eukaryotic Cells:

- are 10x bigger

- are 5-100 um

- have specialized compartments to membrane bound organelles

Describe the key characteristics and functions of the following organelles: nucleus (including nucleolus), endoplasmic reticulum (including smooth vs. rough), Golgi apparatus, lysosome, mitochondrion, chloroplast

Nucleus: contain chromosomes, nucleolus, and nuclear, lamina. Information storage and transmission ribosome subunit assembly, and structural support.

Nucleolus: dense region within the nucleus where ribosomal RNA processing occurs and ribosomal subunit are assembled.

Endoplasmic Reticulum: membrane system continuous with outer membrane of the nucleus.

Smooth ER: lipids produced here, include fatty acids, phospholipids, fast, steroids. Contains enzymes for lipid synthesis and processing.

Rough ER: some proteins produced here, either proteins that become part of the cell membrane or proteins that will be secreted from the cell. Contains receptors for protein synthesis and processing.

Golgi apparatus: stack of flattened, distinct cisterna. Protein, lipid, and carbohydrate processing. Proteins are modified and stored here.

lysosome: organelle unique to animal cells. contains enzymes that hydrolyze carbs, lipids, proteins, nucleic acids. Products exported to cytosol and re-used. Digestion and recycling.

mitochondrion: double membrane, inner one contains enzymes for ATP production.

chloroplast: double membrane, enzymes that use light energy to make sugars. Production of sugars via photosynthesis.

Describe how secreted proteins are transported through the endomembrane system, and the sequence of organelles through which proteins pass

All protein production begins on ribosomes in the cytoplasm.

Proteins with a nuclear localization signal are completed in the cytoplasm, then transported into the nucleus. Proteins with an ER signal sequence trigger a series of molecular interactions that move the ribosome and growing protein to the ER. The proteins move through the endomembrane system and are dispatched from the trans face of the Golgi apparatus in transport vesicles that move through the cytoplasm and then fuse with the plasma membrane releasing the protein to the outside of the cell.

SEE DIAGRAMS

Explain the structural basis of selective permeability of plasma membranes. Predict how a molecule would be transported across the phospholipid bilayer based on the molecule's polarity and size

Some substances can cross the bilayer depending on the size, polarity, and charge of the substance. Small nonpolar molecules, for example, move across bilayers quickly. If the small molecules are polar, the rate of transport decreases. Larger polar molecules and charged substances move across the membrane even slower, if at all. The difference in membrane permeability is a critical issue because controlling what passes between the exterior and interior environments is a key characteristic of cells.

See Diagram for better understanding.

Explain how animal and plant cells behave when put in solutions that are hypotonic or hypertonic to the cell

Hypertonic: when the concentration outside of the cell is greater then inside the cell (meaning less water outside the cell and more inside) then the cell will diffuse water out causing it to shrivel

Hypotonic: when the concentration outside of the cell is less than the inside of the cell (meaning more water outside the cell and less inside) then the cell will diffuse water in causing it to swell

Isotonic: when the concentration outside of the cell is the same as inside the cell (meaning equal amounts of water inside and outside) then the cell will have no change

Use knowledge of how diffusion and osmosis depend on relative solute and water concentration in 2 compartments separated by a selectively permeable membrane

When placed in a two compartment with a selectively permeable membrane. The water will move to the area of higher concentration because there is less water there. Which will also increase the pressure on the side with the higher concentration.

| |^^^^^^^^ |

|^^^^^^^^ : |

| 0.01 : 0.03 |

|______________|______________|

Describe membrane transport processes and identify how each process is similar to or different from the others: passive transport, active transport, co-transport, simple diffusion, facilitated diffusion

passive transport: a movement of biochemicals and other atomic or molecular substances across the cell membrane without the need of energy input.

active transport: the movement of ions or molecules across a cell membrane into a region of a higher concentration, assisted by enzymes and requiring energy.

co-transport: When ATP is used to create a concentration gradient that will then lead to the transport of something unrelated. Also called secondary active transport

simple diffusion: the process where a substance passes through a membrane without the aid of an intermediary such as a protein.

facilitated diffusion: the process of spontaneous passive transport of molecules/ ions across a cell membrane via specific transmembrane protein.

Define: activation energy

The amount of energy required to change the reactants into an unstable state where e's can be rearranged

Define: catalyst

An agent that speeds up the rate of a chemical reaction without being permanently changed or consumed during the reaction. It decreases the Activation energy. Not consumed during the rxn.

Define: enzyme

A protein that acts as a catalyst to speed up a chemical reaction in a cell

Define: substrate

reactant specific for a particular enzyme.

The reactant molecules that bind to an enzyme at the active site and participate in a chemical reaction.

The organic compounds such as soil or rotting wood that fungi use as food.

Define: active site

The location in an enzyme where a chemical reaction takes place

Define: induced fit

The phenomenon that occurs when a substrate(s) binds to an enzyme and the enzyme undergoes a conformational change that causes the substrate(s) to bind more tightly to the enzyme.

Activation energy, catalyst, enzyme, substrate, active site, and induced fit. Use these terms to describe the interaction of an enzyme and its substrate

activation energy: the amount of kinetic energy required to initiate a chemical reaction; specifically, the energy required to reach the transitions state. Enzymes lower the activation energy.

Catalyst: any substance that increases the rate of a chemical reactions without itself undergoing any permanent chemical change. Enzymes are catalysts, they bring substrates together in a precise

orientation that makes reactions more likely.

Enzyme: substance that acts as a catalyst to bring about a specific biochemical reaction.

Substrate: the substance on which an enzyme act.

Active Site: the locations in an enzyme molecule where substrates (reactant molecules) bind and react. Enzymes help substrates collide in a precise orientation so that old bonds can break and new bonds can

form to generate products.

Induced Fit: change in the shape of the active site of an enzyme, as the result of initial weak binding of a substrate, so that it binds substrate more tightly.

Explain how ATP couples exergonic and endergonic reactions in a cell

Exergonic reactions: a chemical reaction that has a change in Gibbs free energy less than zero and can occur spontaneously, releasing heat and/or increasing entropy.

Endergonic reactions: a chemical reaction that has a change in Gibbs free energy greater than zero and is non-spontaneous.

ATP is an endergonic reaction to work because it is an exergonic reaction itself and it couples itself to the endergonic reaction so that the overall reaction is exergonic. The body runs into a problem when a desired reaction is endergonic (non-spontaneous) so it uses another exergonic process to start the non-spontaneous one. It couples the exergonic reaction with the endergonic one so that free energy released from the former reaction drives the other one. For the chosen exergonic reaction, the body generally uses the hydrolysis of ATP; ATP is dispatched to wherever an endergonic reaction needs to take place and the reactions are coupled so that the overall reaction is thermodynamically favored.

Define: competitive inhibitor

bind in the enzyme active site and compete with the substrate, preventing substrate from binding

Define: noncompetitive inhibitor

can bind to an enzyme with or without a substrate at different places at the same time.

Define: allosteric regulation

Bind to enzyme at a position away from active site. Causes enzyme to change shape so that the active site can't bind substrates

Define: cooperativity

a phenomenon in which the shape of one subunit of an enzyme consisting of several subunits is altered by the substrate

Define: feedback inhibition

a type of regulation in which the product of a metabolic pathway inhibits an enzyme that acts early in the pathway, thus preventing the overaccumulation of the product

Predict how low or high concentration of a final product could change concentration of an intermediate if the final product inhibits one of the early reactions in a metabolic pathway

Cofactors:

- Non protein helpers for catalytic activity that are bund tightly to the enzyme as a permanent resident or bound loosely and reversibly along with the substrate

Competitive inhibitors:

- Reduce the productivity of enzymes by blocking substrates from entering active sites

- Can be overcome by increasing the concentration of substrate so that as active sites become available, more substrate molecules that inhibitor molecules are around to gain entry to the sites

Noncompetitive inhibitors:

- Do not directly compete with the substrate to bind to the enzyme at the active site

- They impede enzymatic reactions by binding to another part of the enzyme which causes the enzyme molecule to change its shape on such a way that the active site becomes less effective at catalyzing the conversion of substrate to product

Allosteric inhibitors:

- Attaches to another region of the enzyme

- Changes enzyme shape so active site no longer grabs substrate

What does OIL RIG stand for? And what is the background info about it?

oxidation is loss (of electrons)

reduction is gain (of electrons)

Refers to NAD+ (Nicotinamide adenine dinucleotide)

- Building block: niacin (Vitamin B)

- NAD+ is the oxidized state (has donated electrons / can accept e's from a reaction

- NADH is the reduced state (has accepted electrons (along with a proton = :H-) / can donate e's to another molecule

List 2 electron carriers and explain what they do

The two electron carriers are NAD+ and FAD

NAD is reduced by accepting a single hydrogen (H) and an electron pair from the hydrogen atom (H2 ) and the other hydrogen is freed into the medium. Whereas, FAD is reduced by a full hydrogen atom (H2 ). Hence their reduced forms are written as (NADH+ , H+ ) and FADH2 .

NAD is reduced to NADH in Citric Acid Cycle and glycolysis, it then transfers electrons into electron transport chain at Complex I. Hence helps produce 3 ATPs for every NADH.

FAD is reduced to FADH2 in Citric Acid Cycle, and enter ETC at Complex II and gives 2 ATP for every FADH2 .

For each process of cellular respiration - Glycolysis, Fermentation, Citric acid cycle, Electron transport, Proton motive force, ATP synthesis - answer the following 5 questions:

1. Where does each process happen within the cell?

2. What are the key inputs for each pathway and key outputs of each pathway?

3. Which output of each process is the substrate for further reactions?

4. How does presence or absence of O2 affect each process?

5. Identify conditions that could prevent a process from happening

1. Glycolysis: cytosol of eukaryotes and prokaryotes

Fermentation: cytosol

Citric acid cycle: matrix of mitochondria or cytosol of prokaryotes

Electron transport: inner membrane of mitochondria or plasma membrane of prokaryotes

Proton motive force: inner mitochondrial membrane

ATP synthesis: inner membrane of mitochondria or plasma membrane of prokaryotes

2. Glycolysis:

- Inputs: glucose, 2 ATP, 2 NAD+

- Outputs: 2 pyruvates, 4 ATP (2 net), 2 NADH, 2 H+

Fermentation:

- Inputs: 2 NADH, 2 pyruvic acid

- Outputs: 2 lactate or 2 alcohol, 2 CO2, 4 ATP (2 net), 2 NAD+

Citric acid cycle:

- Inputs: 1 acetyl co-A, 2 NAD+, ADP/GDP, 1 FAD

- Outputs: (2 CO2, 3 NADH, 1 ATP/GTP, 1 FADH2) x 2 (two Acetyl CoA are form from one glucose)

Electron transport:

- Inputs: NADH, FADH2, e-, H+, O2

- Outputs: NAD+, FAD, H2O, H+

Proton motive force:

- Inputs: H+, ADP+Pi

- Outputs: ATP

ATP synthesis:

- Inputs: ADP+Pi, H+

- Outputs: ATP (36 net)

3. Glycolysis: pyruvate for pyruvate oxidation

Fermentation: pyruvate

Citric acid cycle: electrons of NADH and FADH2

Electron transport: proton gradient

Proton motive force: ATP

ATP synthesis: glucose

4. Basically, when there's a lack of oxygen, the electron transfer chain cannot pass on their electron loads (remember oxygen is the final electron acceptor - it forms water accepting the electrons). Thus, the ETC cannot accept electrons from the electron carriers NADH/H+ and FADH2 since all the complexes are in their reduced state. In turn, the 2 electron carriers are locked in their reduced state too, causing a depletion of oxidized state electron carriers NAD+ and FAD+ . This means that Krebs Cycle cannot proceed. In the absence of oxygen, electron transport stops. NADH is no longer converted to NAD+ , which is needed for the first three stages of cellular respiration.

Glycolysis: continues to produce pyruvate

Fermentation: the cycle continues

Citric acid cycle: stops

Proton motive force: continues

ATP synthesis: will never end

5. Glycolysis: no NAD+, large amounts of ATP and citrate will slow the process, no transport

Fermentation: No ATP

Citric acid cycle: No ATP

Electron transport: No ATP

Proton motive force: No ATP

ATP synthesis: No ATP

Explain the specific function of chlorophyll in photosynthesis

It is a compound that absorbs visible light. It absorbs the wavelength of light required to convert water and carbon dioxide into chemical energy during photosynthesis

Compare and contrast the light reactions and the Calvin cycle in terms of location within the chloroplast, inputs, and outputs

Light Reactions:

- location: thylakoids

- inputs: photons and H2O, ADP

- outputs: ATP, NADPH, O2

Calvin Cycle:

- location: stroma

- inputs: ATP, NADPH, CO2

- outputs: Sugar, NADP+, ADP

Explain how the Calvin cycle is linked to the light reactions

Light cycle depends on calvin cycle to produce ADP and NADP + which are needed for the light reactions. The calvin cycle relies on the light reactions to produce ATP and NADPH which are used in the calvin cycle

Compare the process of chemiosmosis during cellular respiration versus during photosynthesis. Include the source of electrons, the location of the electron transport chain, the role of the proton-motive force, the location of ATP synthase, and the location of high and low proton concentrations within the mitochondrion or chloroplast

Cellular Respiration: diffusion of H+ through ATP synthase in inner mitochondrial membrane

- source of electrons: Glucose, NADP, FADH2

- location of electron transport chain: inner mitochondrial membrane

- role of the proton-motive force: potential energy is converted to kinetic energy

- location of high and low concentrations: high outside membrane and low inside the membrane

Photosynthesis: the synthesis of organic materials using light, water, and carbon dioxide

- source of electrons: H2O, P680

- location of electron transport chain: between PS II and PS I

- the location of ATP synthase: thylakoid membrane

- location of high and low proton concentrations: [H+] higher inside thylakoid, lower outside

Describe the role of the following in linear electron flow: Photosystem II, Photosystem I, H2O, primary electron acceptor, electron transport chain, and NADP+ .

Photosystem II :

- Splits water 2H2O ➔ 4e- + 4H+ + O2

- accept P680 wavelengths, red photon

- The electron acceptor pheophytin is reduced with a high energy electron

- The electron is then passed down an electron transport chain (ETC) in the thylakoid fs membrane, Produces a proton gradient and drives ATP production via ATP synthase

Electrons are transferred by plastoquinone (PQ) which is hydrophobic so it can pass through the membrane, to cytochrome complex , from there they are carried by Plastocyanin (PC) which is hydrophilic passes through the thylakoid lumen, carries the electron to PS1.

Photosystem I:

- Makes NADPH

- 700-nm wavelength light, blue

Electron transport chain:

- Transfer of photons across the membrane

NADP+:

- co-factor used in anabolic reactions

Summarization of the Z scheme:

The Z scheme is a model of how photosystems I and II interact. First, photons excite electrons in photosystem II's antenna complex The energy reaches the reaction center and excited electrons are passed down an electron transport chain Photosystem II's reaction center electrons are replaced by splitting water A proton gradient is set up and used to make ATP. At the end of the ETC, the electron is passed to a protein called plastocyanin (PC). PC carries the electron back across the thylakoid membrane. Donates it to the reaction center of photosystem I. Forms a physical link between the two photosystems. Photons excite electrons in photosystem I's antenna complex.The energy reaches the reaction center, and excited electrons are passed to ferredoxin and then to NADP+. Photosystem I's reaction center electrons are replaced from the bottom of the ETC

SEE DIAGRAMS

Describe the role of NADP+ during photosynthesis including its reduction during the light reactions and the subsequent oxidation of NADPH during the Calvin cycle

During the light reactions of photosynthesis, the NADP+ is reduced to NADPH which is an essential step in creating proton gradient across the chloroplast membrane, in this reaction ATP and NADPH (electron transport molecule) are produced. This NADPH is essential for light-independent reactions, which act as electron carrier and its reducing activity is essential for the conversion of carbon dioxide and H2O into organic compounds (such as sugars and proteins)

Predict how a water-soluble or lipid soluble hormone will interact with its cellular receptor

water soluble hormones bind to membrane receptors. G proteins on the inside of the cell are activated. the g proteins has 3 subunits and 1 dissociated bind to GDP and activated. when it encounters Adenylyl cyclase which makes cAMP from ATP. that bind to protein kinase (add phosphate group to this) creating a Phosphorylase. this bind with glycogen to release glucose-6p into blood

lipid soluble binds to intracellular membrane then be incorporated into DNA

https://youtu.be/Nt2r5R0ZO5U

Compare and contrast signal reception between plasma membrane receptors and intracellular receptors, particularly receptor location and type of ligand

Intracellular receptors:

- location: cytoplasm

- type of ligand: receptor

- hormone attaches to extracellular side of receptor

Hormone receptor complex --> starts gene transcription (hydrophilic)

- receptor changes shape

Plasma membrane receptors:

- location: cell surface

- type of ligand: external

- Intracellular 2nd messengers and cytosolic enzymes amplify the signal

Cell cycle: name the phases, describe the events in each phase, know relative length of each phase within the cycle

Interphase

- G1

- S

- G2

Prophase

Prometaphase

Metaphase

Anaphase

Telophase

Cytokinesis

Whole Mitosis phase lasts 24 hours.

Interphase

-G1: Most of the cell's life is spent here. In here it does growth and normal function. Growth includes making more organelles, cytoplasm, and cell membrane. In normal function cellular respiration, photosynthesis, and secretion or absorption occur. Neurons stop after puberty. Epithelial cells divide frequently. and liver cells maybe, maybe never. G1 usually lasts around 11 hours.

- S: all chromosomes are being copied to prepare for mitosis. Usually lasts around 8 hours.

- G2: continued growth and preparation for cell division. You can see the nucleus, chromosomes, and cytoskeleton. Has two centrosomes each with centriole pair. Usually lasts 4 hours.

Mitosis: Total lasts 1 hour.

-Prophase: Usually lasts 10 minutes. Nucleoli disappears and chromosomes coil tightly together to create sister chromatids. The centrosomes start to move away from each other.

- Prometaphase: Lasts around 10 minutes. The nuclear envelope breaks down. Each chromatid has a kinetochore associated with its centrosome. Centrosomes are at opposite poles. Sister chromatids are spread out inside spindle fibers

- Metaphase: Usually lasts 10 minutes. Chromosomes are in center of the cell. Kinetochore of each chromatid is attached to microtubule from opposite poles.

- Anaphase: Usually lasts 10 minutes. Sister chromatids separate in half. Kinetochore microtubules shorten. Daughter chromatids move towards poles.

- Telophase: Usually lasts 10 minutes. Nuclear envelope reforms, making 2 nuclei. Chromosomes decondense. Nucleoli reappears. Spindle microtubules depolymerize.

- Cytokinesis: Usually lasts 10 minutes. Cytoplasm separates making 2 cells. In animal cells cleavage furrow separates.

Mitosis in eukaryotes: Name the 5 phases and describe the events in each phase, including what happens to chromosomes, nucleus, and cytoskeleton

Prophase:

- Nucleoli disappear

- Chromosomes coil tightly (sister chromatids), become first visible under microscope

- 2nd centrosome forms and begin to move away from each other

- spindle forms (microtubule)

Prometaphase:

- Nuclear envelope breaks down

- Each chromatid has a kinetochore (protein complex)

- Centrosomes are at opposite poles

- Microtubules enter nuclear space (some attach to kinetochores or each other from opposite poles)

Metaphase:

- Chromosomes are in center of cell

- Centrosomes at opposite poles

- Kinetochore of each chromatid is attached to microtubules from opposite poles

Anaphase:

- Sister chromatids separate

- Kinetochore microtubules shorten on the positive side (the side connected to the kinetochore)

- Daughter chromosomes move toward poles

Telophase:

- Nuclear envelope reforms (2 nuclei)

- Chromosomes decondense

- Nucleoli reappear

- Spindle microtubules depolymerize

Know the outcome of mitosis: daughter cells are genetically identical to or genetically different from parent cell?

daughter cells are genetically identical from parent cell as well as each other

List and describe 4 physical mechanisms of heat exchange. Categorize animals by source of body heat

Conduction: direct transfer of heat between two physical bodies that are in contact with each other. Rate at which conduction occurs depends on the surface area or transfer, temperature. Differences between two bodies and how well each body conducts heat.

Convection: heat is exchanged between a solid and a moving liquid or gas. Speed of air or water flow increases makes rate of heat between two bodies that are not in direct physical contact electromagnetic radiation coming from any objects warmer than absolute zero.

Evaporation: phase change that occurs when a liquid becomes a gas. Always heat loss

Radiation: electromagnetic radiation any object warner than 0 Kelvin radiates heat

Interpret a figure showing counter-current exchange of heat between blood vessels entering and exiting an appendage

SEE DIAGRAMS

Label a graph showing osmoregulation and osmoconformity across a range of external osmolarities

SEE DIAGRAMS

Identify the three types of nitrogenous waste based on a structural diagram

Urea:

- synthesized from NH3 by vertebrate liver

- less toxic than NH3

- requires less H2O to excrete than NH3

- requires energy to synthesize

- mammals, adult amphibians, sharks, some marine fish

NH2

/

O = C

\

NH2

Uric Acid:

- low toxicity

- excreted as paste

- conserves H2O

- Requires energy to synthesize from NH3

- Birds, reptiles, insects, land snails

O

||

C NH

/ \ / \

HN C \

| || \

C C C = O

// \ / \ /

O NH NH

Ammonia:

- NH3

- most aquatic animals, including bony fish

Compare the advantages and disadvantages of ammonia, urea, and uric acid

Ammonia:

- Advantage: energy is not required for their conversion to a less toxic product.

- Disadvantage: A lot of body water is required to excrete than at a rate that maintains dilute, safe concentrations within the animal

Urea:

- Advantage: less toxic than ammonia, thus animals can tolerate some accumulation of it in their body fluids. Another advantage is that urea does not require large volumes of water for its excretion, thus urea conserves water and reduces the likelihood of toxicity.

- Disadvantage: When producing urea the metabolic synthesis of urea from ammonia requires moderate expenditure of ATP and thus consumes part of an animal's total daily energy budget.

Uric Acid:

- Advantage: toxicity and water solubility is low. Does not require a lot of water to get rid of it.

- Disadvantage: A lot of energy required to make it from ammonia

Explain the function of tight junctions in epithelia in relation to digestion and absorption

Tight Junctions: plasma membranes of neighboring epithelial cells bound together by proteins. Form a continuous seal around cell. Separate outside fluids from inside body.

Explain how structure of the intestinal lining enhances surface area

Intestinal lining = folds of the intestinal wall

Villi = finger like projection of intestine lining made up of epithelial cells, connective tissue, capillaries, and lymph duct.

Microvilli: tiny finger-like projection of apical membrane of intestinal epithelial cells, contains many transport proteins.

(Multiple folds = large surface area)

Trace transfer of biomolecules from intestine into blood or lymph and into organs

Carbohydrates: sugars, starches, grains, found in almost all foods (pasta, fruits, vegetables, etc.). Digestion begins in the mouth, then the small intestine, where simple sugars are absorbed. More complex sugars can be absorbed in large intestine.

Lipids: fats, oils, and butter. Saturated fats: solid at room temperature all single bonds, ex. Animal fats and butter. Unsaturated fats: liquid at room temperature, has at least one double bond, cooking oils. Broken down and absorbed in the small intestine.

Proteins: bean, meats, green leafy vegetables, peanuts. Digestion begins in stomach, broken down into amino acids and absorbed in the small intestine.

Nucleic acids: genetic material. We consume the cells of an organism therefore we are also eating its DNA. Broken down by nucleases DNA and RNA that are released by the pancreas

Label a graph of blood glucose concentration over time, including axis labels and indicating when the stimulus for blood glucose increase occurs, when insulin secretion occurs, when glucagon secretion occurs, when negative feedback is occurring, and when the set point is reached

SEE DIAGRAMS

Explain how each variable in the diffusion rate equation affects gas diffusion rate

If______ large Qs

D ^

A ^

C2-C1 ^

x ⬇

t ^

Qs = quantity substance

D = diffusion coefficient

A = area

C2 - C1 = concentration gradient

x = membrane thickness

t = time

Explain how properties of respiratory surfaces affect gas diffusion rate

The moistness prevents cell membrane from collapsing and the plasma membrane must be in contact with an aqueous solution. The rate of diffusion is proportional to the surface area across which it occurs and inversely proportional to the square of the distance through which molecules must move. Gas exchange is fast when the area for diffusion is large and the path for diffusion is short.

Explain how cooperativity enhances hemoglobin O2 loading at high O2 concentration and O2 unloading at low O2 concentration and interpret a graph of hemoglobin oxygen binding

Cooperativity means that when oxygen binds, the hemoglobin molecule changes shape, making it easier for the 2nd, 3rd, and 4th oxygen molecules to bind

SEE DIAGRAMS

Compare the structure of arteries, veins, and capillaries in terms of tissue layers present and size of each layer

Arteries: (3 layers)

Function: carry blood away from heart

- Outer: connective tissue & elastic

- Middle: smooth muscle

- Inner: 1 cell thick (made of endothelial cells)

Veins (3 layers)

Function: carry blood towards heart

- Outer: connective tissue

- Middle: smooth muscle

- Inner: Endothelial cells

Predict the effect of slow flow rate on diffusion rate across capillary walls, using Fick's Law of Diffusion

Total area of capillaries is very large

Flow rate depends on the cross-section of the pipe

Flow rate is slower in capillaries

Allows time (t) for diffusion

Explain how transpiration and the properties of water interact to move water from roots to leaves

Cohesion links water molecules together through hydrogen bonds

Transpiration creates tension among hydrogen bonds between H2O molecules inside xylem

Evaporation at top of water column creates negative pressure

Water flows upward toward lower pressure

Compare the vascular system of plants to the vascular system of animals

Vessel structure

Fluid

Flow circuits or direction

Motive force (suction or pressure, how generated)

Plants:

- Vessel structure: tracheid (dead), sieve tube elements, xylem, phloem

- fluid: water, ions, sugars

- flow circuit/direction: xylem (one way: roots --> leaves), phloem (leaves --> roots --> leaves)

- motive force: suction, transpiration

Animals:

- Vessel structure: arteries, capillaries, venules, veins

- fluid: blood, plasma, water, nutrient, ions

- flow circuit/direction: one way (circulates)

- motive force: heart pump (pressure)

Explain how osmotic concentration in sieve tube elements generates pressure and determines flow direction in phloem

Sugar moves because of turgor pressure

High solute concentration inside a cell draws in water

Water moving into a plant cell increases pressure until wall pressure is induced

the flow direction will depend on where lower pressure is aka where the cells have less solute

pressure is generated because as the cell swells, the cell wall will push back and that results in turgor pressure

Describe the pathway of long distance signaling, including endocrine cell, hormone, means of delivery, and target cell

Hormone is secreted

- Hormone: chemical signals produced by the endocrine cell.

Endocrine cells: cells that secrete hormones into the interstitial fluid or into capillaries, but not into a duct or lumen.

Hormone enters the vascular system (circulatory or phloem)

The hormone travels to a target cell in another part of the body

Target cell: any cell with a receptor

- Receptor: A protein that binds a specific hormone.

Example: insulin released by the pancreas → insulin travels to signal muscle and fat cells.

Compare similarities and differences between pathways of local and long distance signaling

Local signaling:

a. Gap junctions - allow ions to move between cells carrying an electrical signal.

b. Plasmodesmata - cytoplasm flows between phloem cells

c. Paracrine: chemical secreted from one cell signals a neighboring cell.

Long distance signaling:

a. Hormone is secreted, it enters the vascular system, travels to target cells in another part of body. In both local and long-distance signaling, only specific target cells recognize and respond to a given signaling molecule. Local regulators and hormones are both physical molecules in the cell. Local signaling includes paracrine signaling (when animal cells communicate using secreted messenger molecules that travel only short distances) and synaptic signaling (occurs in the animal nervous system when a neurotransmitter is released in response to an electric signal). Long-distance signaling includes hormonal signal (celled endocrine signaling in animals, specialized cells release hormones, which then travel to target cells via the circulatory system)

- Hormone is secreted

- Enters vascular system (circulatory or phloem)

- Travels to target cell in another part of body

- Example:

- Pancreas secretes insulin

- Insulin travels in blood to signal muscle and fat cells

Similarities → hormone has to be secreted from cell, receptors on the target cells detect them

differences → long distance is just endocrine, local signaling is paracrine and electrical signaling

SEE DIAGRAM

Draw a motor neuron, labeling the dendrites, cell body, axon, and axon terminals, indicating where a stimulus is detected, where an action potential is initiated, and where the action potential travels to the target cell

Dendrites: receive signals from other neurons

Cell body: contains nucleus and organelles

Axon: transmits signals to other neurons or muscles

SEE DIAGRAM

Explain how resting potential is generated, including the transport proteins required, the ions transported and the ratio at which Na+ and K+ are transported

charge difference across a cell membrane of animal cells. It develops because of Na+ and K+ movement through Na+ -K+ ATPase, passive K+ channels, and passive Na+ channels. Na+ -K+ ATPase pumps 3 Na+ out and 2 K+ into the cell. Passive K+ channels are always open; K+ leaves cells but the [K+ ] is higher inside the cell.

Cl- and proteins keep the K+ from leaving so quickly, makes the inside more negative

SEE DIAGRAM

Explain the changes in ion movement that initiate and propagate an action potential, including the role of voltage-gated Na+ channels, voltage-gated K+ channels, sodium-potassium pump, passive Na+ channels, and passive K+ channels

Resting State: The gated Na+ and K+ are closed. Ungated channels maintain the resting potential.

Depolarization: A stimulus opens some sodium channels. Na+ inflow through those channels depolarizes the membrane. If the depolarization reaches the threshold, it triggers an action potential.

Rising phase of action potential: Depolarization opens most sodium channels, while the potassium channels remain closed. Na+ influx makes the inside of the membrane positive with respect to the outside.

Falling phase of action potential: Most sodium channels become inactivated, blocking Na+ inflow. Most potassium channels are open, permitting K+ outflow, which makes the inside of the cell negative again.

Undershoot: The sodium channels close but some potassium channels are still open. As these potassium channels close and the sodium channels become unblocked (though still closed) the membrane returns to its resting state.

SEE DIAGRAM

Predict the effect of altered ion permeability on resting or action potentials

If the Na+ gates close, Na+ will no longer go through the cell membrane. If the K+ gates close, K+ will no longer go through the membrane either. The charges inside of the cell and outside the cell would be reversed.

If the Na+ gate is inhibited, there will be no action potential at all