Exam 4- Chapter 6 PART 1

Question 1

How do chemoorganoheterotrophs funnel substances towards the same metabolic pathways?

Answer 1

breaking the sources into intermediates then funneling them into same glycolytic pathway

Question 2

Why do chemoorganoheterotrophs funnel substances into same pathway

Answer 2

saves on genomic space
more efficient

Question 3

Ways cells can get energy?

Answer 3

aerobic respiration
anaerobic respiration
fermentation

Question 4

Examples of aerobic respiration

Answer 4

glycolytic pathways
TCA cycle
Electron transport chain with oxygen

Question 5

Types of fermentation

Answer 5

heterolactic
homolactic
alcohol
mixed acid

Question 6

aerobic respiration

Answer 6

process than can completely catabolize an organic source to CO2

Question 7

anaerobic respiration

Answer 7

uses electron carriers other than oxygen

Question 8

fermentation

Answer 8

NADH produced by glycolysis is re-oxidized into NAD+

Question 9

Amphibolic pathways

Answer 9

function as both catabolic and anabolic pathways
some enzymes work in both directions and some work in only one

Question 10

Why do some enzymes in amphibolic pathways work in both directions?

Answer 10

saves on genomic space

Question 11

Why do some enzymes in amphibolic pathways work in only one direction?

Answer 11

allows for independent regulation

Question 12

Examples of amphibolic pathways

Answer 12

Embden-meyerhof pathway (glycolysis)
pentose phosphate pathway

Question 13

aerobic, anaerobic, and fermentation- which produces the most energy

Answer 13

Aerobic

Question 14

Why does aerobic produce the most energy?

Answer 14

oxygen has a high redox potential
this creates a larger differential and greater proton gradient
allows for more ATP to be made

Question 15

Embden-Meyerhof pthway

Answer 15

most common route for the breakdown of glucose into pyruvate
works in presence or absence of oxygen

Question 16

Where does Embden-Meyerhof pathway occur?

Answer 16

cytoplasmic matrix of ALL major groups of microorganisms, plants, and animals

Question 17

Two phases of Embden-Meyerhof:

Answer 17

energy investment
energy generating

Question 18

start products of glycolysis

Answer 18

glucose
2 ADP
2 NAD+

Question 19

End products of glycolysis

Answer 19

2 pyruvate
2 ATP
2 NADH

Question 20

What happens to the carbon in glycolysis?

Answer 20

begins as a 6-carbon molecule
At the end of the investment phase, it is split into two 3-carbon molecules

Question 21

How many ATP and NADH are generated in glycolysis

Answer 21

4 ATP (only net 2)
2 NADH

Question 22

substrate phosphorylation

Answer 22

enzymatically coupled reaction producing ATP
transfers a phosphate group from a reactive intermediate made during catabolism to ADP

Question 23

What does it mean by coupled reaction

Answer 23

releases energy when P is pulled off intermediate
uses energy when P is put on ADP

Question 24

Oxifative phosphorylation

Answer 24

ATP molecule synthesized directly from the oxidation of CO2
Electrons are passed through an electron proton system
which powers ATP synthase

Question 25

What does ATP synthase do

Answer 25

Produces ATP from ADP and P

Question 26

Which generates more ATP oxidative or substrate-level phosphorylation?

Answer 26

oxidative

Question 27

What happens during transition/prep step?

Answer 27

glycolysis ends with pyruvate molecule (2) transition step generates an electron carrier (NADH) through decarboxylix reaction left with Acetyl-CoA to enter TCA

Question 28

Where does TCA occur in Eukaryotes

Answer 28

mitochondria

Question 29

Where does TCA occur in prokaryotes?

Answer 29

cytoplasm

Question 30

What is TCA a major source of?

Answer 30

carbon skeletons used in biosynthesis

Question 31

For each Acetyl-CoA molecule what does TCA generate?

Answer 31

2 molecules CO2 3 molecules NADH 1 molecule FADH2 1 molecule GTP (2 acetyl-CoA enzymes generated in prep)

Question 32

What type of regulation is for TCA

Answer 32

allosteric

Question 33

What regulates the TCA cycle?

Answer 33

isocitrate dehydrogenase

Question 34

Two ways TCA allosterically regulates:

Answer 34

feedback inhibition precursor activation

Question 35

Feedback inhibition-TCA

Answer 35

increase in ATP/high concentrate of NADH will cause regulation

Question 36

precursor activation-TCA cycle

Answer 36

An increase in ADP/NAD+ will cause positive regulation

Question 37

How much ATP is synthesized directly from the oxidation of glucose to CO2?

Answer 37

4 total - 2 from glycolysis - 2 from TCA

Question 38

Most ATP is made when...

Answer 38

NADH and FADH2 are oxidized in ETC

Question 39

How much NADH and FADH2 do we get from oxidation of glucose?

Answer 39

10 NAD and 2 FADH - 2 NADH from glycolysis - 2 NADH from prep/trasition steo - 6 NADH from TCA - 2 FADH2 from TCA

Question 40

Redox potential

Answer 40

The tendency of a molecule to acquire electrons

Question 41

How do electrons flow for redox potential?

Answer 41

from carriers with negative redox potentials to acceptors with positive redox potentials

Question 42

What does negative redox potential mean?

Answer 42

does not like to acquire electrons will give away electrons (donors)

Question 43

What does positive redox potential mean?

Answer 43

likes to acquire electrons acceptors

Question 44

What is the result of a greater difference between conjugate pair?

Answer 44

A greater proton gradient and more ATP generated

Question 45

How ETC works

Answer 45

A series of electron carriers operate together to transfer electrons from NADH/FADH2 to the terminal electron acceptor Electrons flow from negative donors to positive acceptors

Question 46

What makes up ETC

Answer 46

Four complexes organized by redox potential Complex I is most negative Complex IV is most positive

Question 47

What does it mean that ETC is like a bucket brigade?

Answer 47

Each carrier is reduced and then reoxidized as it moves through the four complexes Carriers are constantly recycled

Question 48

Why not just have 1 complex

Answer 48

Four complexes capture more energy to pump protons Require smaller steps because differential is so large

Question 49

Proton Motive Force and ATP Synthase

Answer 49

transfer of electrons is accompanied by proton movement across the inner membrane ATP synthase uses the proton motive force down the gradient to catalyze ATP synthesis

Question 50

How much ATP does ETC generate?

Answer 50

28-34

Question 51

Chemiosmotic hypothesis

Answer 51

As electrons flow, they generate energy to pump protons and build up a gradient Potential energy is converted to kinetic and used to run ATP synthase

Question 52

Why does ETC generate so much more ATP?

Answer 52

Extracts energy from high energy electron carriers to generate ATP synthesis Glycolysis/TCA build ATP directly

Question 53

Where is ETC in Eukaryotes

Answer 53

mitochondrial membrane

Question 54

Where is ETC in Prokaryotes

Answer 54

plasma membrane

Question 55

What connects electron transport carriers in Eukaryotes?

Answer 55

Coenzyme Q and cytochrome c

Question 56

What are differences between mitochondrial and bacterial ETC?

Answer 56

different electron carriers carriers may be branches and may be shorter

Question 57

Why does Bacterial/Archaeal ETC produce less ATP?

Answer 57

generally pumps fewer protons- creates a smaller gradient

Question 58

ATP synthase is composed of two parts

Answer 58

F0 type: imbedded in membrane F1: located in cytoplasmic space

Question 59

How does ATP synthase work?

Answer 59

As protons move through it they cause the gamma subunit to rotate Rotation alters active site conformation This facilitates the addition of phosphate onto ADP

Question 60

ATP yield in Eukaryotic cells- Aerobic respiration

Answer 60

2 ATP from glycolysis (substrate level phosphorylation) 2 ATP from TCA (substrate level phosphorylation) 28-34 ATP from ETC (oxidative phosphorylation) TOTAL YIELD per glucose: ~34 ATP