2.2 Intro to metab - Glycolysis

Question 1

catabolism

Answer 1

molecule breakdown

Question 2

do catabolic processes release/consume energy?

Answer 2

release energy

Question 3

what is anabolism? does it release/consume energy?

Answer 3

build bigger molecules

consumes energy

Question 4

what is the function of glycolysis?

Answer 4

glucose breakdown

Question 5

regulation of metabolism ensures _______ of materials in a pathway

Answer 5

unidirectional flow

Question 6

flow of material through a metabolic pathway depends on:

Answer 6

1. supply of substrates
2. removal of products
3. properties of enzymes

Question 7

____ is the universal energy carrier

Answer 7

ATP

Question 8

ATP is generated by the ________ of metabolic fuels

Answer 8

oxidation

Question 9

the energy released by the oxidation of food molecules is stored temporarily in ______

Answer 9

activated carrier molecules such as FADH2, NADH, & NADPH

Question 10

Biosynthetic and Degradation pathways are ____

Answer 10

distinct

Question 11

ATP generation occurs in 2 ways:

Answer 11

1. substrate phosphorylation

2. oxidative phosphorylation

Question 12

what is substrate-level phosphorylation?

Answer 12

formation of ATP from ADP and a phosphorylated intermediate, rather than from ADP and inorganic phosphate, Pi, as is done in oxidative phosphorylation

Question 13

is substrate-level phosphorylation oxygen dependent or independent?

Answer 13

oxygen independent

Question 14

what is oxidative phosphorylation?

Answer 14

where a molecule is oxidized and the energy is captured by NADH and FADH2 and then transferred by a series of electron carriers to create a chemical gradient that can be used to power ATP synthase

Question 15

is oxidative phosphorylation oxygen independent or dependent?

Answer 15

oxygen dependent (aerobic)

Question 16

what are redox reactions? what does the process involve?

Answer 16

when organic molecules are broken down by cell respiration, the chemical energy is transferred by means of redox reactions
the reduction of one chemical species and the oxidation of another

oxidation is coupled to reduction

Question 17

in redox reactions, if electrons are lost, this is called

Answer 17

oxidation

Question 18

in redox reactions, if electrons are gained, this is called

Answer 18

reduction

Question 19

in most of the oxidation and reduction reactions in metabolism, electrons(e-) will be moved with ____

Answer 19

protons (H+)

Question 20

what are electron carriers?

Answer 20

small organic molecules that readily cycle between oxidized and reduced forms and are used to transport electrons during metabolic reactions.

Question 21

NAD+ and FAD are involved in what process?

they accept _______ and carry them ultimately to the ______ where the energy is used to ______

Answer 21

involved in cellular respiration

“high energy” electrons

ETC

synthesize ATP

Question 22

NADH and FADH2 produce ___ ATPs and ___ ATPs respectively

Answer 22

2.5 ; 1.5

Question 23

why does FAD/FADH2 differ from NAD+/NADH?

Answer 23

FAD/FADH2 are bound tightly to enzymes which use them. whereas NAD+/NADH can move freely within the cytosol

Question 24

NADP+ is not used for ATP synthesis but its electrons provide the energy for certain biosynthesis reactions such as those involved in ______

Answer 24

lipid synthesis

Question 25

NADH is produced in the _____ during glycolysis

Answer 25

cytosol

Question 26

NADH is produced in the cytosol during glycolysis. However, the NADH oxidation process in the cell occurs primarily via the _____ pathway in the ______

Answer 26

ETC; mitochondria

Question 27

what can’t NADH do?

Answer 27

NADH cannot cross the mitochondria membrane

Question 28

the ________ facilitates the translocation of electrons across the mitochondrial membrane

Answer 28

malate-aspartate shuttle

Question 29

explain the process for malate-aspartate shuttle.

Answer 29

cytoplasmic malate dehydrogenase (MDH) reduces OAA –> malate, while oxidizing NADH to NAD+.

malate then enters the mitochondrion where the reverse reaction is performed by mitochondrial malate dehydrogenase

Question 30

where does glycolysis occur?

Answer 30

cytosol

Question 31

where does TCA/citric acid cycle occur?

Answer 31

mitochondrial matrix

Question 32

where does oxdiative phosphorylation occur?

Answer 32

inner mitochondrial membrane

Question 33

where does gluconeogenesis occur?

Answer 33

some in cytosol, some in matrix

Question 34

what are the net products of glycolysis?

Answer 34

2 pyruvate
2 H2O
2 ATP
2 NADH + 2H+

Question 35

the glycolysis products are syntheszied through what type of phosphoryaltion

Answer 35

susbtrate-level phosphorylation

Question 36

what is the terminal electron acceptor in aerobic respiration?

Answer 36

molecular oxygen (O2)

Question 37

although glycolysis does not require O2, in the absence of O2 the NADH produced cannot be used to generate ATP via the ETC.

in anaerobic conditions, what becomes an obligatory end product?

Answer 37

lactate becomes an obligatory end product because the need for regeneration of NAD+

Question 38

when is anaerobic glycolysis useful?

Answer 38

• RBCs (lack mitochondria)

- high muscle activity (O2 limiting)

Question 39

order/preference of metabolic fuel of RBCs

Answer 39

1. Glucose

Question 40

order/preference of metabolic fuel for brain

Answer 40

1. glucose

2. ketone bodies (only used in starvation ((very poor fuel source for brain))

Question 41

order/preference of metabolic fuel for liver

Answer 41

1. glucose
   - – glucose used to form building blocks for biosynthesis and is converted to glycogen (essential for providing fuel to other tissues during fasting)
2. fatty acids
   - – during starvation, the liver converts fatty acids to ketone bodies
3. amino acids
   - – AAs are metabolized to provide energy or used to synthesize proteins, glucose, etc

Question 42

order/preference of metabolic fuel for muscle

Answer 42

1. glucose (and glycogen stores)

2. fatty acids and ketone bodies (FA’s major fuel in resting stage)

Question 43

order/preference of metabolic fuel for adipose tissue

Answer 43

1. glucose –> needs glucose to syntheszie TAG

2. fatty acids