Module 3

Question 1

catabolic pathways

Answer 1

release energy

Question 2

What do cells degrade complex organic molecules that are rich in potential energy into?

Answer 2

simpler waste products that have less energy

Question 3

fermentation

Answer 3

partial degradation of sugars without the use of oxygen

Question 4

aerobic respiration

Answer 4

the most prevalent and efficient catabolic pathway, uses oxygen

Question 5

anaerobic respiration

Answer 5

uses no oxygen

Question 6

cellular respiration

Answer 6

includes bothe aerobic and anaerobic processes

Question 7

cellular respiration equation

Answer 7

Organic compounds + oxygen =carbon dioxide + water + energy

C6H12O6 + 6O2 = 6CO2 + 6H2O + Energy (ATP + heat)

Question 8

The breakdown of glucose is?

Answer 8

exergonic

Question 9

What do catabolic processes do?

Answer 9

make energy(ATP) that is used to perform cellular work

Question 10

oxidation

Answer 10

loss of electrons from one substance

Question 11

reduction

Answer 11

addition of electrons to another substance

Question 12

reducing agent

Answer 12

electron donor

Question 13

oxidizing agent

Answer 13

electron acceptor

Question 14

the more electronegative an atom…

Answer 14

the more energy is required to take an electron away from it

Question 15

Why are organic molecules that have an abundance of hydrogen excellent fuels?

Answer 15

because their bonds are a source of “hilltop” electrons who energy may be released as these electrons “fall” down an energy gradient when they are transferred to oxygen

Question 16

Glycolysis

Answer 16

occurs in the cytosol; breaks glucose into two 3-carbon pyruvate molecules

Question 17

Citric Acid Cycle

Answer 17

occurs in the mitochondrial matrix; completes the breakdown of glucose

Question 18

Electron transport chain

Answer 18

hydrogens are combined with oxygen and release energy; forms water as a by-product

Question 19

How are glucose and other organic fuels broken down?

Answer 19

in a series of steps, each one catalyzed by an enzyme

Question 20

What happens in Electron Transport Chain and Chemiosmosis?

Answer 20

occurs in the inner membrane of the mitochondria; releases energy for the production of ATP via oxidative phosphorylation (some is made via substrate-level phosphorylation during glycolysis and the citric acid cycle)

Question 21

Net energy yield per glucose molecule

Answer 21

2 ATP + 2 NADH

Question 22

Products of Krebs/Citric Acid Cycle

Answer 22

3 NADH, 1FADH2, 1 ATP

Question 23

What are the pyruvates converted into in the Krebs Cycle?

Answer 23

acetyl coenzyme A (acetyl CoA) and CO2

Question 24

What are electrons stored as in the Krebs Cycle?

Answer 24

electrons are stored in NAD+, which makes it NADH

Question 25

I the Kreb's cycle, what does coenzyme FAD do and what does it turn into?

Answer 25

acts as an electron carrier and is changed into FADH2

Question 26

Where do electron carriers move electrons after the Kreb's Cycle?

Answer 26

the electron transport chain

Question 27

What is the composition of the electron transport chain pathway?

Answer 27

Collection of molecules embedded in the inner membrane of the mitochondrion in eukaryotic cells (plasma membrane in prokaryotes)

Question 28

What are most components of the elctron transport chain?

Answer 28

proteins

Question 29

What happens to electron carriers as they go through the electron transport chain?

Answer 29

alternate between reduced and oxidized states as they accept and donate electrons; reduced as accept electrons from “uphill” and oxidized as lose them “downhill” to a more electronegative atom

Question 30

What is the last atom accepting electrons and what does it do?

Answer 30

oxygen; very electronegative, forms water

Question 31

function of Chemiosmosis

Answer 31

Couples the energy released by the electron transport chain to the production of ATP

Question 32

ATP synthase

Answer 32

produces ATP from ADP

Question 33

What happens to hydrogens in chemiosmosis? What is the result of this?

Answer 33

pumped across the membrane against their concentration gradient; when hydrogen flows back across by diffusion, phosphorylation is powered and ATP is produced

Question 34

What acts like a molecular motor?

Answer 34

chemiosmosis?

Question 35

What does the exergonic flow of electrons from NADH and FADH2 do?

Answer 35

pump hydrogen across the membrane, from the mitochondrial matrix into the intermembrane space; when hydrogens move back across the membrane by diffusion, they can only move through ATP synthase channels; this drives the phosphorylation of ATP and ATP is produced

Question 36

Chemiosmosis prudces about

Answer 36

32-34 ATP

Question 37

Total ATP during aerobic respiration

Answer 37

36-38 ATP

Question 38

anaerobic respiration

Answer 38

takes place in certain prokaryotic organisms, there is an electron transport chain, but oxygen is not the final electron acceptor

Question 39

fermentation

Answer 39

no electron transport chain; an expansion of glycolysis

Question 40

alcohol fermentation

Answer 40

pyruvate is converted into ethanol (ex: yeast, bacteria)

Question 41

lactic acid fermentation

Answer 41

pyruvate is reduced to form lactate (lactic acid)

Question 42

what is lactic acid used by?

Answer 42

fungi, bacteria, and human muscle cells

Question 43

obligate anaerobes

Answer 43

can carry out only fermentation or anaerobic respiration, and cannot survive in the presence of oxygen

Question 44

facultative anaerobes

Answer 44

can make enough ATP to survive using either fermentation or aerobic respiratio

Question 45

What can be used by cellular respiration to make ATP?

Answer 45

fats, proteins, sucrose, starch, etc

Question 46

What can glycolysis accept a wide range of for catabolism?

Answer 46

carbohydrates

Question 47

What must proteins do before they can be used as fuel?

Answer 47

must be broken down

Question 48

fats

Answer 48

beta oxidation breaks the fatty acids down to carbon fragments, which enter the citric acid cycle

Question 49

Biosynthesis (anabolic pathways)

Answer 49

food provides both energy and the carbon building blocks of the body; some are used directly, some broken down into monomers and then used

Question 50

What does the regulation of cellular respiration use?

Answer 50

negative feedback mechanism – feedback inhibition most common

Question 51

What happens if ATP concentration is dropped?

Answer 51

more is made