AP BIology Unit 3 cellular respiration

endergonic

A chemical reaction that requires the input of energy in order to proceed.

exergonic

Chemical reactions that release energy

non spontaneous

Endergonic reactions are _______ _______

Energy coupling

The use of an exergonic process to power an endergonic one

activation energy

Energy needed to get a reaction started

catalyst

substance that speeds up the rate of a chemical reaction

catalysts

_______ reduce the amount of energy to start a reaction

enzymes

cells get help from _____ to reduce activation energy

substrate

reactant which bonds to enzyme

enzyme-substrate complex

A temporary complex formed when an enzyme binds to its substrate molecule(s).

Active site

a region on an enzyme that binds to a protein or other substance during a reaction.

Reaction specific

each enzyme works with a specific substrate

enzymes

______ are not consumed in reaction

temperature, salinity, pH, enzyme concentration, substrate concentration, activators, inhibitors

Factors that affect enzymes

salinity

The total amount of dissolved salts in a water sample

sucrase

breaks down sucrose

protease

breaks down proteins

lipase

breaks down lipids

DNA polymerase

catalyzes the formation of the DNA molecule

pepsin

breaks down proteins in the stomach (polypeptides)

Lock and Key model

The model of the enzyme that shows the substrate fitting perfectly into the active site

conformational change

an alteration of the structure of the protein that impacts that protein's function

synthesis

Active site orients substrate in correct position for reaction during _______

digestion

active site binds substrate and outs stress on bonds that must be broken, making It easier to separate molecules in ________

permease

transports lactose into the cell

increase

does the reaction rate decrease or increase as enzyme concentration increases?

level off

When increasing enzyme concentration, the reaction rate will eventually ____ ____

maximum

when increasing substrate concentration, the reaction rate will eventually level off because it has reached its ____

optimum temperature

The temperature at which an enzyme is most active

cofactors

nonprotein enzyme helpers

coenzymes

non protein, organic molecules that help enzymes (ex. vitamins)

competitive inhibition

inhibitor and substrate complex compete for the active site

Noncompetitive inhibitor

inhibitor binds to site other than active site

allosteric site

A specific receptor site on some part of an enzyme molecule remote from the active site.

irreversible inhibitor

inhibitor permanently binds to enzyme

allosteric regulation

conformational changes by regulatory molecules

regulatory molecules

ions that bind directly to an enzyme's active site

inhibitor

A substance that slows down or stops a chemical reaction

activator

keeps enzyme in active form

sequentially

enzymes are embedded in membrane and arranged _____

feedback inhibition

process in which the product or result stops or limits the process

cooperativity

substrate acts as an activator

endergonic

organisms are ______ systems

synthesis, reproduction, movement, active transport, temp regulation

What do we need energy for?

adenosine triphosphate

What does ATP stand for

AMP

adenine + ribose + Pi=__

ADP

AMP + Pi=__

ATP

ADP + Pi =__

inorganic phosphate gro

Pi= __

Phosphorylation

The metabolic process of introducing a phosphate group into an organic molecule.

kinase

catalyzes the transfer of a phosphate group from ATP to a specified molecule

ATP synthase

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

Chemiosmosis

A process for synthesizing ATP using the energy of an electrochemical gradient and the ATP synthase enzyme

cellular respiration

Process that releases energy by breaking down glucose and other food molecules in the presence of oxygen

Electrons

____ move as part of an H atom

oxidation

adding O, removing H, lose electrons, release energy, exergonic

removing O, adding H, gain electrons, stores energy, endergonic

Electron carriers

molecules that can carry high energy electrons through the electron transport chain

electron carriers

NADH and FADH2

glycolysis, pyruvate oxidation, krebs cycle, electron transport chain

4 metabolic stages

glycolysis

the breakdown of glucose by enzymes, releasing energy and pyruvic acid.

pyruvate

Three-carbon compound that forms as an end product of glycolysis.

2ATP + 2NADH

net yield of glycolysis

cytosol

where does glycolysis occur

10

how many steps in glycolysis?

glucose + 2ATP

reactants of glycolysis

isomerase

changes molecules structure

Phosphofructokinase

rate limiting enzyme in glycolysis

dehydrogenase

An enzyme that catalyzes a chemical reaction during which one or more hydrogen atoms are removed from a molecule.

Step 1 of glycolysis

Phosphate group is transferred from ATP to glucose, making glucose-6 phosphate (step)

Step 2 of glycolysis

glucose-6 phosphate is converted into its isomer, fructose-6 phosphate (step)

Step 3 of glycolysis

a phosphate group from ATP is transferred to fructose-6 phosphate, producing fructose-1,6biphosphate ( this step is catalyzed by phosphofructokinase)

Step 4 of glycolysis

Fructose-1,6bisphosphate splits to form two 3-carbon sugars ; creates DHAP and glyceraldehyde-3-phosphate (step)

Step 5 of glycolysis

DHAP is converted into glyceraldehyde-3-phosphate(step)

investment phase

First 5 steps of glycolysis

payoff phase

last 5 steps of glycolysis

Step 6 of glycolysis

Glyceraldehyde-3-phosphate is oxidized and NAD+ is reduced to NADH and H+ ; molecule is phosphorylated, creating 1,3-biphosphoglycerate (step)

step 7 of glycolysis

1,3-biphosphoglycerate donates one of it's phosphate groups to ADP, making a molecule of ATP and turning into 3-phosphoglycerate in the process (step)

step 8 of glycolysis

3-phosphoglycerate in converted into its isomer, 2-phosphoglycerate (step)

step 9 of glycolysis

2-phosphoglycerate loses a molecule of water , becoming phosphoenolpyruvate (PEP) which is an unstable molecule (step)

step 10 of glycolysis

PEP donates its phosphate group to ADP, making a second ATP; after losing a phosphate, PEP becomes pyruvate

hexokinase

enzyme that phosphorylates six-carbon sugars to form hexose phosphate

glycolysis

anaerobic stages of cellular respiration

linker step, krebs cycle, electron transport chain

aerobic stages of cellular respiration

another molecule must accept H from NADH

how is NADH recycled to NAD+

fermentation

Process by which cells release energy in the absence of oxygen

lactic acid fermentation

The conversion of pyruvate to lactate with no release of carbon dioxide.

alcohol fermentation

The conversion of pyruvate to carbon dioxide and ethyl alcohol.

endosymbiosis

symbiosis in which one of the symbiotic organisms lives inside the other.

Step 1 of Krebs cycle

CoA joins with a 4-carbon molecule (oxaloacetate) releasing the CoA group group and forming and forming citrate, which is a 6 carbon molecule (step)

2nd step of Krebs cycle

citrate is converted into it's isomer isocitrate. This process has two steps, removal of a water molecule and then the addition of a water molecule (step)

3rd step of Krebs cycle

isocitrate is oxidized and releases a CO2 molecule, leaving behind a 5-carbon molecule. NAD+ is reduced to form NADH (step)

4th step of Krebs cycle

the 5 carbon molecule α-ketoglutarate is oxidized, reducing NAD+ to NADH and releasing a CO2 molecule. An unstable compound succinyl CoA is formed. (step)

5th step of Krebs cycle

The COA of succinyl COA is replaced with a phosphate group, which is then transferred to ADP to make ATP. 4 carbon molecule succinate is formed (step)

GTP

guanosine triphosphate

step 6 of Krebs cycle

succinate is oxidized, forming fumerate. Two hydrogen atoms are transferred to FAD, producing FADH2 (step)

step 7 of Krebs cycle

Addition of a water molecule rearranges bonds in the substrate. Fumarate --> malate (step)

step 8 of Krebs cycle

The substrate (malate) is oxidized, reducing NAD+ to NADH and regenerating oxaloacetate.

2 ATP

how many ATP does Krebs cycle produce

Electron transport chain

series of proteins build into the inner mitochondrial membrane; transport of electron down the ETC linked to pumping H+ to create the gradient