BIO 101 Exam 1

Topics: Scientific Method, Biomolecules, Cell Membranes, Photosynthesis, Cellular Respiration, Cell Reproduction

Steps of the Scientific Method

Bond type that connects amino acids

Peptide bonds (covalent)

Partial negative charge of one molecule is attracted to partial positive charge on another molecule

hydrogen bonds

organic molecules and compounds contain _______

carbon

two atoms share electrons in this bond

covalent

Bonds held together by difference in charges

ionic

Hydrogen bonds are weak electrical attractions; why do hydrogen bonds take so much energy to break?

hydrogen bonds have extreme quantity

Unique properties of water caused by hydrogen bonds

Attraction between the partially negative oxygen of one water molecule and the partially positive hydrogen of an adjacent water molecule.

Why is water a polar molecule?

Electrons are not shared equally, electrons are concentrated around oxygen atom

Why is water the “universal solvent”

Polar property makes it good at dissolving other polar molecules

Structure of proteins

chain of amino acids connected by peptide bonds

Function of proteins

regulate where cell reactions occur, support cell structure, aid in movement/mobility, transport molecules across cell membranes

Levels of protein structure

1. Peptide Bonds: sequence of amino acids held together by strong covalent peptide bonds

2. Secondary Level: hydrogen bonds between amino acids, form alpha helixes & beta sheets

3. Tertiary Level: R group interacts with bond types → forms 3D structures

4. Quaternary Level: interactions between tertiary structures

Structures of Nucleic Acids

DNA- Adenine+Thymine, Guanine+Cytosine

RNA- Adenine+Uracil, Guanine+Cytosine

Monomer of protein

amino acid

Monomer of nucleic acids

nucleotides

What are nucleotides made of?

Phosphate group, pentose sugar, nitrogenous base

Function of DNA

stores genetic information (blueprint)

Function of RNA

RNA carries out functions + directs protein synthesis

Structure of carbohydrate

long chains of monosaccharides create polysaccharides

Monomer of carbohydrates

monosaccharides: glucose, ribose, frutose

Function of carbohydrates

Energy storage (glycogen), energy source, building biomolecules

Building blocks of lipids

hydrocarbons, fatty acids, glycerol

Structure of phospholipids

made of triglycerides, glycerol, and phosphates, hydrophillic head, hydrophobic tail

Function of lipids

long term energy storage, hormone regulation, nuclear envelope

Characteristics of living things

-able to survive & reproduce autonomously

-composed of one or more cells

-sense & respond to environment

-obtain energy from the environment

-maintain homeostasis

-can evolve as a group

Structure of unsaturated vs saturated fats

saturated fats have a carbon-carbon single bond (harder to break down), unsaturated fats have a carbon-carbon double bond (easier to break down)

Structure of viruses

DNA in a membrane sheath, can’t reproduce without a host

Structures of cell membrane

-phospholipid bilayer: hydrophillic heads on the outside, hydrophobic tails on the inside

-transport proteins

-receptor proteins

What does the selectively permeable membrane filter for?

-charge exclusion (non-polar molecules can pass through hydrophobic core)

-size exclusion

-receptor proteins

-transport proteins

Receptor protein

sites where a molecule from another cell can bind to

Function of receptor proteins

recieve molecular signals, communicate with other proteins, respond to surroundings

Transport proteins

gates, channels, and pumps that allow molecules to move in/out of the cell

Passive transport

spontaneous movement of a substance without addition of energy (high to low concentration)

Active transport

movement of a substance requiring input of energy (low to high concentration)

Simple diffusion

small, unchagred molecules ot water, oxygen, CO2 can slip through large molecules in the phosophlipid bilayer

Osmosis

simple diffusion of water

Isotonic

equal concentration of water in cell and outside solution

Hypertonic

Cell has lower concentration of solute than environment

Hypotonic

Cell has higher concentration of solute than environment

Facilitated diffusion

passive transport of hydrophilic substances

-high → low concetration

-transport proteins or vesicles

Vesicles

cell “bulge” that moves across the membrane to transport molecules in/out

Endocytosis

process by which substances are transported into cells by vesicles

Receptor mediated cytosis

receptor proteins recongnize surface characteristics of substances to be incorporated into the cell

Phagocytosis

“cellular eaating”

-where molecules are ingested via selective endocytosis

-used to ingest and destroy viral particles

Pinocytosis

“cellular drinking”

-nonselective

-cell captures surrounding fluid (takes in everything in the solution)

Exocytosis

substance to be expelled from cell is released by a vesicle

Bulk flow

transport of a large amount of molecules in/out of a cell, used in:

-receptor mediated cytosis

-phagocytosis (white blood cells)

-pinocytosis (fluid)

Metabolism

describes all chemical reactions that occur inside of cells including those that capture, store, or release energy

Metabolic passages

close chains of linked events that produce biomolecules in a cell (eg, amino acids, nucleotides)

ATP

adenosine triphosphate

-used to store energy and move it to other parts of the cell

-created by adding a phosphate group to ADP

-created in cellular respiration

anabolism

metabolic pathways that create complex molecules from smaller compounds

catabolism

metabolic pathways that release energy by breaking down complex compounds

ADP

adenosine diphosphate

-molecule leftover when phosphate at the end of ATP breaks off to release energy

Where does glycolysis occur?

the cytoplasm

Where does the Krebs Cycle occur?

mitochondrial matrix

Where does Oxidative Phosphorylation occur?

the inner mitochondrial membrane

Inputs of Calvin cycle/light-independent reaction

CO2, ATP, NADPH (comes from light-dependent reaction)

Outputs of Calvin cycle/light independent reaction

NADP+, ADP, glucose

Inputs of the light-dependent reactoin

-ATP from sunlight

-water from the environment

NADP+ and ADP from the light independent reaction

Outputs of the light-dependent reaction

ATP, NADPH, oxygen

Competitive enzymes

changes shape of the enzyme/binds to active site so the substrate can’t bond

Role of electrons in photophosphorylation

provide energy for proton pump to move H+ ions

Non-competitive enzymes

binds to enzyme without filling the receptor site

Role of enzymes

lower activation energy → speeds interactions

Role of enzymes in the Thylakoid

helps create a hydrogen gradient and electron gradient

Label the photophosphorylation step in the light dependent reaction

Label the Calvin Cycle

Label the photosynthesis diagram

Inputs of glycolysis

sugars (mostly glucose)

Outputs of glycolysis

-2 pyruvates

-ATP

-NADH

Outputs of the Krebs cycle

-CO2

-NADH

-FADH2

-ATP

Which step of cellular respiration happens twice per molecule?

Krebs cycle

Reaction of cellular respiration

C6H12O6 + 6O2 →6CO2 + 6H2O + 32 ATP + heat

Inputs of the Krebs cycle

-pyruvate

-NAD+

-FAD

-ADP

Inputs of oxidative phosphorylation

-NADH

-FADH2

-O2

-ADP

Why is heat an important output of oxidative phosphorylation?

maintains homeostasis through body temperature

Role of oxygen in oxidative phosphorylation

Final electron acceptor → allows you to produce metabolic water

What happens if there is no oxygen in cellular respiration?

Short term: anaerobic respiration (fermentation)

Long term: cells die

What does fermentation do?

turns pyruvate into lactic acid to regenerate NAD+

Which step(s) of cellular respiration can occur without oxygen?

only glycolysis

Terminal electron acceptor in photophosphorylation

NADP+

Terminal electron acceptor in oxidative phosphorylation

Oxygen

What provides electrons to the electron transport chain in photophosphorylation?

water

Oxidative phosphorylation

mitochondria use oxidative phosphorylation to transfer energy from food into chemical energy of ATP

Photophosphorylation

chloroplasts use photophosphorylation to transfer light energy into chemical energy of ATP

Complete the glycolysis diagram

Complete the Krebs cycle diagram

Complete the oxidative phosphorylation diagram

Induced fit

when an enzyme changes shape when molecules bind to the active site

Rubisco

enzyme that speeds up the Calvin cycle

Interphase

longest stage of the cell cycle

-cells spend most of their life in interphase (~90%)

-cells take in energy, manufacture proteins, grow larger, conduct specilaized functions

G1 phase

-first period of growth in size, protein content, and increased ATP production

-replicating organelles

-first checkpoint

G1 checkpoint

cell division pauses if cell is too small, nutrition is inadequate, and/or DNA is damaged

S phase

synthesis- DNA is replicaed

G2 phase

-last stage of interphase

-second period of growth (size/protein content)

-organelles replicate

-checkpoint before cell division

G2 checkpoint

cell division pauses if cell is too small, nutrition is inadequate, DNA is damaged, and/or if chromosome replication is incomplete

What happens if cells wrongfully pass a checkpoint?

damaged cells can replicate “runaway cell division”

-cancer

-organ dysfunction

-organs can form incorrectly

Asexual reproduction

the process by which parent cells generate clones (genetically identical)

Binary fission

the process by which a prokaryotic cell reproduces, essentially just splitting in half down the middle