cellular respiration (glycolysis, krebs)

Question 1

sum total of all chemical reactions in living cells

Answer 1

Metabolism

Question 2

degrade macromolecules and other
molecules to release energy

Answer 2

catabolic reactions

Question 3

used to synthesize macromolecules for cell growth, repair, and reproduction

Answer 3

anabolic reactions

Question 4

Can divide metabolism into 4 groups:

Answer 4

carbohydrates, lipids, amino acids, nucleotides

Question 5

pathways can take different forms: (3)

Answer 5

linear
cyclic
spiral

Question 6

product of one reaction is substrate for another
e.g. glycolysis

Answer 6

linear

Question 7

regeneration of intermediates

e.g. Krebs cycle

Answer 7

cyclic

Question 8

same set of enzymes is used repeatedly

e.g. fatty acid synthesis, beta-
oxidation

Answer 8

spiral

Question 9

each pathway may have branch points for ??? to enter or leave

Answer 9

metabolites

Question 10

Reasons why metabolic reactions have many steps:

Answer 10

1) energy input and output can be controlled

2) enzymes can catalyze only a single step of a pathway

3) provides opportunities to establish control points, which are essential for cell function

Question 11

occurs in discrete steps as it it transferred to acceptors a little at a time

Answer 11

energy transfer

Question 12

Major Catabolic Pathways

begins with ??? of polymers (exogenous)

Answer 12

extracellular digestion

Question 13

??? in mouth and intestine work on starch

Answer 13

amylase

Question 14

??? starts in stomach and finished via ??? and ???

Answer 14

protein digestion;
pancreatic proteases and intestinal peptidases

Question 15

triacylglycerols hydrolyzed to fatty acids by phospholipases

Answer 15

lipid digestion

Question 16

absorption occurs in ???—> ???—> ???

Answer 16

intestine
blood
body

Question 17

major catabolic pathways can also have ??? sources, such as glycogen and triacylglycerols

Answer 17

endogenous

Question 18

catabolism yields 3 possible compounds:

Answer 18

1) acetyl CoA
2) nucleoside triphosphates
3) reduced coenzymes

Question 19

major catabolic pathways starts with ??? (glucose catabolism), ???, ???, ???

Answer 19

glycolysis;
citric acid cycle;
polysaccharide mobilization;
oxidative phosphorylation

Question 20

are metabolized for excretion, not energy production

Answer 20

nucleotides

Question 21

There are several types of group transfer reactions that involve ATP:

Answer 21

1) phosphoryl group transfer
2) nucleotidyl-group transfer
3) thioesters

Question 22

Another class of energy-rich molecules.
Energy can be donated in oxidation-reduction reactions

Answer 22

reduced coenzyme

Question 23

§ Purpose: catabolism of glucose to provide ATPs and NADH molecules
§ Also provides building blocks for anabolic pathways.

Answer 23

glycolysis

Question 24

glycolysis:

Electrons are transferred to oxidizing agents ??? or ???

Answer 24

NAD+ or FAD.

Question 25

glycolysis: glucose➡️??? ??? and ??? produced All enzymes (and reactions) are ???

Answer 25

pyruvate; 2 ATPs and 2 NADH; cystolic

Question 26

net reaction of glycolysis

Answer 26

glucose + 2ADP + 2NAD+ +2Pi ➡️ 2 pyruvate + 2ATP + 2NADH +2H+ +2H2O

Question 27

glycolysis can catabolize sugars other than glucose: (3)

Answer 27

fructose lactose mannose

Question 28

glycolysis step 1:

Answer 28

Glucose + ATP → Glucose-6-phosphate + ADP + H+ hexokinase

Question 29

glycolysis step 2:

Answer 29

Glucose-6-phosphate → Fructose-6-phosphate glucose 6-phosphate isomerase

Question 30

glycolysis step 3:

Answer 30

Fructose-6-phosphate + ATP → Fructose-1,6-bisphosphate + ADP + H+ phosphofructokinase-1 (PFK-1)

Question 31

which steps in glycolysis requires ATP

Answer 31

1 and 3

Question 32

glycolysis step 4:

Answer 32

Fructose-1,6-bisphosphate → Dihydroxyacetone phosphate + Glyceraldehyde-3-phosphate aldolase

Question 33

glycolysis step 5:

Answer 33

Dihydroxyacetone phosphate → Glyceraldehyde-3-phosphate triose phosphate isomerase

Question 34

which steps in glycolysis are done twice?

Answer 34

6-10 once for each of the 2 G3P

Question 35

glycolysis step 6:

Answer 35

Glyceraldehyde-3-phosphate + Pi + NAD+ → 1,3-Bisphosphoglycerate + NADH + H+ glyceraldehyde 3-phosphate dehydrogenase

Question 36

glycolysis step 7:

Answer 36

1,3-Bisphosphoglycerate + ADP → 3-Phosphoglycerate + ATP Phosphoglycerate kinase

Question 37

which steps in glycolysis produces ATP?

Answer 37

7 and 10

Question 38

glycolysis step 8:

Answer 38

3-Phosphoglycerate → 2-Phosphoglycerate phosphoglycerate mutase

Question 39

glycolysis step 9:

Answer 39

2-Phosphoglycerate → Phosphoenolpyruvate + H2O enolase

Question 40

glycolysis step 10:

Answer 40

Phosphoenolpyruvate + ADP + H → Pyruvate− + ATP Pyruvate kinase

Question 41

Under anaerobic conditions, cells must be able to regenerate ??? or ??? will stop.

Answer 41

NAD+; glycolysis

Question 42

NADH is usually regenerated by ???, but that requires O2.

Answer 42

oxidative phosphorylation

Question 43

FATE OF PYRUVATE (3)

Answer 43

1) alcoholic fermentation 2) lactate fermentation 3) entry into citric acid cycle

Question 44

There are 2 anaerobic pathways that use NADH and regenerate NAD+.

Answer 44

1) alcoholic fermentation 2) lactate fermentation

Question 45

Conversion of pyruvate to ethanol

Answer 45

alcoholic fermentation

Question 46

Lactate causes muscles to ache. Also produced by bacterial fermentation of lactose.

Answer 46

lactate fermentation

Question 47

There are three enzymes that can be regulated:

Answer 47

1) hexokinase 2) phosphofructokinase-1 3) pyruvate kinase

Question 48

Organisms derive much of their energy from the Kreb's Cycle, also referred to as the ???. The Kreb's cycle is an ??? process that comprises ??? definite steps.

Answer 48

Tricarboxylic Acid cycle; aerobic; eight

Question 49

In order to enter the Kreb 's Cycle, pyruvate must first be transformed by ??? complex located in the mitochondria into ???

Answer 49

pyruvate dehydrogenase; acetyl-coA

Question 50

In the presence of ??? organisms are capable of using the Kreb's Cycle. The reason oxygen is required is because the ??? and ???produced in the Kreb's Cycle are able to be oxidized in the ??? thus replenishing the supply of ???

Answer 50

oxygen; NADH and [FADH2] ; electron transport chain (ETC); NAD+ and [FAD].

Question 51

net reaction for Kreb's Cycle

Answer 51

Acetyl-CoA + 3NAD + FAD + GDP + Pi + 2H2O ---> 2CO2 + 3NADH + FADH2 + GTP + CoA + 3H+

Question 52

REGULATION OF KREB CYCLE There are 2 enzymes that are regulated:

Answer 52

1) isocitrate dehydrogenase 2) a-ketoglutarate dehydrogenase

Question 53

* allosterically activated by high [Ca2+] and high [ADP] * allosterically inhibited by high [NADH]

Answer 53

isocitrate dehydrogenase

Question 54

* allosterically activated by high [Ca2+] * allosterically inhibited by high [NADH] and high [succinyl CoA]

Answer 54

a-ketoglutarate dehydrogenase

Question 55

for every molecule of glucose, how many times does the Kreb's Cycle happen?

Answer 55

twice, each for every pyruvate

Question 56

with oxygen, in animals, pyruvate can be converted to?

Answer 56

lactate

Question 57

TCA cycle products

Answer 57

Acetyl-CoA Citrate Isocitrate a-ketoglutarate Succinyl-CoA Succinate Fumarate Malate Oxaloacetate

Question 58

GTP

Answer 58

(Guanosine Triphosphate)

Question 59

TCA Cycle net produce every Acetyl CoA

Answer 59

3NADH + FADH2 + ATP

Question 60

TCA cycle enzymes

Answer 60

citrate synthase aconitase isocitrate dehydrogenase a-ketoglutarate dehydrogenase succinyl-coA synthetase succinate dehydrogenase fumarase malate dehydrogenase