Bio 1500 Exam 2

Memorize the four postulates of natural selection. 

1. Individuals vary in their traits (phenotypes)

2. Offspring will have the same/similar phenotype as parents

3. More offspring are produced then they’re offspring survive to reproduce

4. Those with favorable traits reproduce most and pass their alleles to the next generation

Evolution: change in allele frequencies in a population over time

Population: Group of individuals that interbreed and reproduce

Fitness: Ability to survive and reproduce in an environment

Adaptation: Trait that increases fitness of the individual with said trait relative to others without it

Similarities Between Diffusion and Facilitated Transport: Both Facilitated Transport and Diffusion move molecules from a lower concentration to a higher concentration without expending cellular energy

Differences Between Diffusion and Facilitated Transport: In facilitated transport, polar molecules pass through the non-polar cellular membrane with the help of carrier proteins and selective and gated protein channels. Diffusion does not require extra assistance to transport molecules across the cellular membrane

Describe the importance of gated proteins: They are important because they allow electrical energy to be built up within the cell and select what to take and let leave out of the membrane.

Identify factors that influence the rate of diffusion and whether those factors increase or decrease the rate 

1.  The Extent of the Concentration Gradient: The greater the difference high and low concentration, the faster diffusion is going to be

2. Mass of Molecules: The larger the molecule, the slower it moves

3. Higher Temperature increases molecule movement

4. Distance Travelled: The greater the distance, the slower the diffusion rate

5. Surface Area: The larger the surface area, the faster diffusion will take place

6. Plasma Membrane Thickness: The thicker the membrane, the lower the rate of diffusion

Selection on body size

1. sexual selection: competition among males favors large size

2. selection for female fecundity (egg/offspring production number/ birthing time): large size

3. selection for early reproduction: smaller body→ less time to maternal develop: small size

4. limited food availability: small size

5. predation: large size in predator, small size in prey

6. locomotion: flight favors small size

7. temperature: cold favors large size in mammals, small size in ectotherms, e.g. insects

Identify the level of a question according to Bloom's Taxonomy 

• Creating: putting information together in an innovative way, new or original work

• Evaluating: making judgements, justifying a stand or decision

• Analyzing: breaking the concept into parts and understanding how each part is related to one another

• Applying: using the knowledge gained in new ways or new contexts

• Understanding: explain ideas or concepts, construct the meaning of something

• Remembering: recalling facts and basic concepts

Hydrolysis: A chemical process that splits a molecule by adding water.

Dehydration Synthesis: A chemical reaction in which two molecules are bonded together with the removal of a water molecule.

Carbohydrates: simple sugars, ex. gulcose, chitin, celluose

Lipids: Fatty acids, ex. bacon fat, beeswax, olive oil

Proteins: Amino acids, ex. enzymes, antibodies, hemoglobin

Nucleic Acids: Nucleotides, ex. DNA, RNA, ATP

Prokaryotes:

• oldest cell type

• small and simple

• lack nucleus

• Lack organelles

• single celled

Eukaryotes:

• evolved from procaryote

• larger and more complex

• contain nucleus

• contain organelles

• single celled or multicell

Animal cell vs. Plant cell

Centrioles, lysosomes, and flagellum are three organelles in animal cells that are not found in most plant cells. Likewise, plant cells have central vacuoles, cell walls and chloroplasts, which are not in animal cells.

Plasma membrane - a phospholipid bilayer with embedded proteins that separates the internal contents of the cell from its surrounding environment.

Cell wall - maintains cell shape

Ribosomes - protein synthesis 

Cytoplasm - the cell's entire region between the plasma membrane and the nuclear envelope (a structure we will discuss shortly). It is comprised of organelles suspended in the gel-like cytosol, the cytoskeleton, (70 - 80% water)

Cytosol - the fluid inside a cell, excluding organelles.

Flagella - long, hair-like structure that extends from the plasma membrane and moves the cell

Cytoskeleton - protein fiber network that collectively maintains the cell's shape, secures some organelles in specific positions, allows cytoplasm and vesicles to move within the cell, and enables unicellular organisms to move independently

Nucleus - cell organelle that houses the cell’s DNA and directs ribosome and protein synthesis

Golgi apparatus - eukaryotic organelle comprised of a series of stacked membranes that sorts, tags, and packages lipids and proteins for distribution

Endoplasmic Reticulum (ER) - 

series of interconnected membranous structures within eukaryotic cells that collectively modify proteins and synthesize lipids

Mitochondria - cellular organelles responsible for carrying out cellular respiration, resulting in producing ATP, the cell’s main energy-carrying molecule

Chloroplast - plant cell organelle that carries out photosynthesis

Lysosome - organelle in an animal cell that functions as the cell’s digestive component; it breaks down proteins, polysaccharides, lipids, nucleic acids, and even worn-out organelles

Endomembrane system - synthesis of proteins, transport of proteins into membranes and organelles or out of the cell, metabolism and movement of lipids, and detoxification of poisons

Vesicles - Transports substances in and out of the cell (via the plasma membrane) and between organelles. Some are formed by the Golgi apparatus or the endoplasmic reticulum, while others are formed at the cell surface.

Vacuole - membrane-bound sac, somewhat larger than a vesicle, which functions in cellular storage and transport

1. Identify the function of cellular respiration 

To make ATP

2. Memorize the inputs and outputs of cellular respiration 

Inputs: Glucose and oxygen

Outputs: ATP, and by-products of CO2 and water

3. Memorize the main steps of cellular respiration 

1. Glycolysis: Glucose is broken into pyruvate, that then yields 2 ATP and NADH

2. Pyruvate prep/citric acid cycle: Pyruvate is broken down that then produces more NADH and FADH2. CO2 is a byproduct of this step.

3. Electron Transport Chain (ETC): The NADH and FADH2 from Step 2 supply electrons. Redox reactions occur during this step. This is where one molecule loses an electron which is oxidation, then another molecule gains the electron lost by the previous, or reduction.

What is the electron transport chain?

Is a sequence of electron carrier molecules that shuttle electrons, down a series of reactions that release energy; used to make ATP.

How does the electron transport chain work? What does it accomplish?

1. Electrons supplied by NADH and FADH2 from citric acid cycle

2. Series of redox reactions: one molecules loses an electron (oxidation) + another molecule gains it (reduction)

3. As electrons are passes, it moves to a lower energy state; the energy is used to pump H+ (protons) across the membrane, generating a proton gradient that stores energy

4. Oxygen is the final acceptor of the electrons, producing H2O as a byproduct

5. H+ reenters the mitochondrial matrix through ATP synthase (enzyme), generating ATP

What is the role of proteins in the electron transport chain?

Proteins release the energy used to pump the H+ (protons) to create the gradient

What is the role of O2 in cellular respiration?

It is the final electron acceptor

What happens to cells with the absence of O2?

If oxygen is cut off, there is a pause in the electron transport chain. The electron "holders" in ETC hold 2 electrons, and oxygen is needed to take the 2 electrons. So, therefore, if no oxygen is present the electrons stop moving in the chain. This overall halt results in no ATP being produced and the person dying/cells dying to kill the organism.

6. Describe the roles of the proton gradient and ATP synthase 

What is a proton gradient?

The product of the electron transport chain. A higher concentration of protons outside the inner membrane of the mitochondria than inside the membrane is the driving force behind ATP synthesis.

What is the role of a proton gradient?

Drives production of ATP synthase, to create ATP

What is ATP synthase?

Large protein that uses energy from H+ ions to bind ADP and a phosphate group together to produce ATP

What is the role of ATP synthase?

It uses a hydrogen ion (proton) gradient to make ATP

7. Trace the flow of energy through the steps of cellular respiration 

The energy begins with the glucose, or other molecule, and the 2 ATP molecules from glycoses. At the end of the citric acid cycle, the energy is in NADH and FADH2. At the end of the ETC, the energy is in ATP to be used.