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Flashcards in The Catabolism of Glucose Deck (48)
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1

the aim of glucose metabolism is the generate ___

ATP

2

ATP can be used to drive _____ reactions to form other molecules such as amino acids and sugars

biosynthetic

3

which cell types require glucose as an energy source?5

- erythrocytes - exclusively use glucose as an energy source
- retina
- renal medulla
- brain
- all cancer cells

4

why can diabetes cause eye damage

diabetes can result in the retina being starved of glucose

5

____ converts oxidised precursors to reduced biosynthetic products using -_____ and __ and generating ___

anabolism, NADPH and H+, generating NADP+ (NOT NAD+ like catabolism)

6

_____ converts reduced fuel into oxidised products using ___- and generating ____ and ___

catabolism, NAD, generating NADH and H+(NOT NADPH like anabolism)

7

oxygen is a very reactive molecule but glucose has a sufficiently stable structure so oxygen can be stored in this -OH bonds.

glucose is like a coiled spring - ready to release energy

The body must metabolise the ___ isoform of glucose

D isoform

8

describe lactose disaccharides

galactose beta 1,4- glucose

9

describe maltose disaccharides

glucose alpha 1,4- glucose

10

describe sucrose disaccharides

glucose alpha 1,2 - fructose

11

describe cellobiose disaccharides

glucose beta 1,4- glucose §

12

____ is the storage form of glucose

glycogen

13

what 4 things can glucose be converted to? what is its fate?

1. glycogen, starch, sucrose, conversion to lipids - STORAGE
2. pyruvate
3. lactate
4. ribose - 5- phosphate

14

glucose is converted to pyruvate by _____ through ____ ___

oxidation through aerobic glycolysis

15

glucose is converted to lactate by _____ through ____ ___

fermentation by anaerobic glycolysis

16

glucose is converted to ribose - 5 phosphate by _____ through the ____ ___ pathway

oxidation through the pentose phosphate pathway

17

the function of aerobic glucose metabolism is to generate ____ which is then converted to _____

pyruvate, acetyl co a

18

the purpose of the citric acid cycle is to oxidise _____ and generate ___ and ____

NADH and FADH2

19

what are the two mechanisms of glucose transport into cells

1. via Na/glucose symporters - this does not require energy
2. via passive facilitated diffusion glucose transporters (there are 5 GLUT transporters )

20

The glucose GLUT transporters have different kinetic properties

GLUT1 - present in the ____
GLUT2 - present in the ____ and ___ ___
GLUT3 - present in the ____
GLUT4 - present in the ____ and ___ ____
GLUT5 - present in the ____

GLUT1 - present in the brain
GLUT2 - present in the liver and beta cells
GLUT3 - present in the brain
GLUT4 - present in the muscle and adipose tissue
GLUT5 - present in the gut

21

the GLUt transporters in the brain have a ___ Km

low - can utilise glucose at very low concs

22

the GLUT transporters in the liver and beta cells have a ___ Km

high - so they can control glucose

they are insulin dependent

23

the GLUT 4 transporters in muscle and adipose are ____ dependent

insulin

24

the GLUT 5 transporters in the gut transport _____

fructose

25

glycolysis - overall numbers

glucose + __ADP + __ Pi + __NAD+

-------->

_ pyruvate + _ ATP +_ H2O + _ NADH + _ H+

glucose + 2 ADP + 2 Pi + 2 NAD+
------->
2 pyruvate + 4 ATP +2 H2O + 2 NADH + 2 H+

26

what are the two important intermediates between glucose and pyruvate?

glucose first converted to fructose - 1- 6 bisphosphate using 2 ATP in the process

this is converted to 2 triose phosphates (3 carbon)

these are then converted to 2 pyruvates (by losing phosphates) generating 4 ATP and 2NADPH + H+

27

glycolysis in stages
Stage 1: glucose is ____ and _____

Stage 2: __ interconvertible ___-carbon molecules are formed - each triose loses ___ phosphate groups

Stage 3: generation of ___

Stage 1: glucose is trapped and destabilised

Stage 2: two interconvertible three-carbon molecules are formed. each triose loses 2 phosphate groups

Stage 3: generation of ATP

28

there are two major cellular needs in glycolysis

production of ___

provision of ___ ____ s for _____ reactions

production of ATP
provision of building blocks for synthetic reactions

29

there are ___ control points in glycolysis - caused by ____ catalysing ____ reactions

3, enzymes, irreversible

30

which enzyme controls substrate entry ?

hexokinase