glucose and carbohydrate

Question 0

how much energy is released from one NADH

Answer 0

220 kJ/mol

Question 1

what is the amount of energy released from one ATP

Answer 1

30.5 kJ/mol

Question 2

how many ATP is produced through the anaerobic and aerobic metabolism of 1 glucose

Answer 2

anaerobic - 2 ATP

aerobic - 32 ATP

Question 3

what kind of sugars are glucose, galactose and fructose

Answer 3

glucose and galactose - aldose

fructose - ketose

Question 4

which GLUT transporter is in muscle and adipose tissue

Answer 4

GLUT4

Question 5

which GLUT transporter is in the liver and pancreas

Answer 5

GLUT 2

Question 6

which GLUT transporter is universal for all cells of the body

Answer 6

GLUT 1

Question 7

what substrates are used for gluconeogenesis

Answer 7

glycerol or amino acids (NEVER FROM FATS)

Question 8

which ion is bound to free ATP

Answer 8

Mg

Question 9

how does hyperglycaemia cause blindness and gangrene

Answer 9

covalent reaction of free glucose in the blood with amines of the blood vessel walls –> brittle –> prone to clots –> blindness or gangrene

Question 10

fasting level of glucose

Answer 10

4-5mM

Question 11

what is the blood test to test for uncontrolled diabetes other than fasting glucose

Answer 11

Hb A1C

Question 12

in which places of the body is anaerobic metabolism essential

Answer 12

in RBCs, lens and retina (lack mitochondria)

Question 13

equation for glycolysis

Answer 13

glucose +2NAD+ + 2ADP + 2Pi –>

2pyruvate + 2NADH + 2ATP + 2H20

Question 14

why is it that anaerobes need to consume more glucose that aerobes

Answer 14

because aerobes get 32ATP per molecule, while anaerobes only get 2

Question 15

function of hexokinase in glycolysis

Answer 15

combines glucose and ATP –> glucose 6-P

Question 16

function of phosphohexose isomerase in glycolysis

Answer 16

conversion between glucose6-P and fructose 6-P

Question 17

what is the function of phosphofructokinase-1 in glycolysis

Answer 17

converts fructose 6-P to fructose 1,6bisP

then commited to make pyruvate

Question 18

what is the feedback mechanism for glycolysis

Answer 18

phosphofructokinase is only active when cells have low ATP

Question 19

which substrate can be used for short bursts of anaerobic metabolism

Answer 19

creatine

Question 20

how much glucose does the brain need per day

Answer 20

120g

Question 21

what is galactosaemia

Answer 21

enzyme defect so the body cannot metabolise galactose

Question 22

what is fructose

Answer 22

the ketose form of glucose

Question 23

what is bad about fructose

Answer 23

• does not elicit insulin release from the pancreas
• fails to increase the production of leptin from fat cells
• does not appear to suppress the production of ghrelin
• is broken down mostly into the backbone of triacyglycerols

Question 24

which sugar can FAs be metabolised to

Answer 24

fructose (not glucose)

Question 25

what are the physical signs that humans are omnivores

Answer 25

dentition - incisors and canines for tearing, and molars for chewing plants gut structures - short - for meat and plant digestion

Question 26

why are low Gycaemic index diets recommended

Answer 26

because it avoids the high peak glucose levels that can lead to insulin resistance

Question 27

what happens to the extra glucose that we dont need for glycogen synthesis in the fed state

Answer 27

The NADPH drives cholesterol synthesis and fat synthesis - cholesterol synthesis through oxidation via pentose phosphate pathway - fat synthesis via oxidation via glucolysis --> pyruvate --> fat

Question 28

is alpha or beta isomers of glucose present in the body

Answer 28

alpha | beta in plants - eg cellulose

Question 29

which GLUT receptor is in muscle

Answer 29

GLUT 4

Question 30

why is that muscles dont "share" their glucose stored as glycogen

Answer 30

because they dont have glucose-6-phosphatase to release free glucose into the blood

Question 31

in what form do muscles use their stored glycogen and how is it made

Answer 31

glucose-1-P | broken down by glycogen phosphase

Question 32

what is the process called when the liver breaks down its glycogen and releases glucose into the blood

Answer 32

gluconeogenesis

Question 33

what kind of receptor is the insulin receptor

Answer 33

tyrosine kinase

Question 34

why do elite athletes benefit from carbo loading

Answer 34

it maximises the glycogen load in the muscles prior to exercise so they can use this during exercise and not rely on other substrates for a longer period

Question 35

how is glycogen formed (from what precursor)

Answer 35

glucose-6-phosphate crosslinked between Cs 6 and 1

Question 36

what is the noticable sign that your muscles have switched from using glycogen to fatty acids

Answer 36

you "hit the wall"

Question 37

explain the chemical and osmotic properties of glycogen

Answer 37

``` chemically inert (due to ester linkages) osmotically equivalent to 1 glucose molecule ```

Question 38

what causes Pompes disease

Answer 38

lack of alpha-1,4-glucosidase | causes accumulation of glycogen in the lysosomes (as this enzyme isnt there to break it down

Question 39

when is glycogen broken down

Answer 39

- in the fasting state | - in response to adrenaline (exercise

Question 40

how does adrenaline cause glycogen breakdown in the muscle

Answer 40

activation of a cyclase --> cAMP --> cascade --> 1000s of molecules of glucose-1-P --> glucose for muscle

Question 41

effect on blood sugar of free sugars (mono and disaccharides)

Answer 41

- cause a rapid rise in blood sugar | - stimulates insulin release

Question 42

effect on blood glucose of short chain carbohydrats

Answer 42

- may be unabsorbed and fermented by gut bacteria

Question 43

effect on blood glucose of starch

Answer 43

most starch is rapidly digested and absorbed giving a response much like free sugar

Question 44

what were the constituents of the typical cave man diet

Answer 44

high protein, more polyunsaturated fats, fibre, calcium and vitamin C and low sodium

Question 45

4 parts of the wheat husk and what is in each

Answer 45

bran - rich in nutrients and fibre endosperm - starch and proteins germ - rich in vitamins and minerals husk - inedible part of the grain

Question 46

what causes Beriberi

Answer 46

thiamine deficiency

Question 47

what food is beriberi associated with?

Answer 47

corn - people whose diets were primarily corn did not have enough thiamine --> beriberi

Question 48

what is the effect of fibre in the GIT

Answer 48

delays stomach emptying and increases the speed through the GIT

Question 49

how does fibre have a protective effect against diverticulitis and haemorrhoids

Answer 49

fibre is highly hydrophilic --> keeps water with it --> faeces is not hard and therefore less risk of irritation of the intestine or anal sphincter

Question 50

what is the glycaemic index

Answer 50

ranking of carbohydrates based on their immediate effect on blood glucose