36

Question 1

You need to supply your brain with fuels - how much glucose per day?

Answer 1

Uses 120 g of glucose per day

Question 2

What other fuel do other tissues (not brain) need?

Answer 2

Fatty acids mainly

Question 3

We need to conserve _____ as much as possible to maintain ______ and ________

Answer 3

Protein
Strucuture
Function

Question 4

What hormone is mainly involved during survauval while starving

Answer 4

glucagon is the main hormone involved - it is produced by pancreas a cells when blood glucose drops

Question 5

What kind of hormone is glucagon? How many fatty acids?

Answer 5

Peptide hormone
29 amino acids

Question 6

Triacylglycerol stored in adipose tissue amounts to at least…..

Answer 6

15kg of fat

Question 7

Triacylglycerol stores in adipose tissue is enough energy to survive at least ___ days of starvation

Answer 7

40

Question 8

What hormone stimulates lipolyis

Answer 8

Glucagon

Question 9

What is used at fuel in aerobic tissues (except Brian?)

Answer 9

Fatty acids (via beta oxidation)

• not brain, brain used glucose

Question 10

How much energy per frames of fat?

Answer 10

• 38-40kj

Question 11

How long can we last without food? - calculation

Answer 11

Question 12

Answer 12

Question 13

Why can’t we just use glycerol to make glucose?

Answer 13

Brain needs ~120 g glucose per day
We get around 20 g of glucose from glycerol each day. Where do we get the extra glucose?

Question 14

How many grams of glycogen in the liver?

Answer 14

90-120g

Question 15

What happens to liver glycogen during starvation?

Answer 15

mobilised back to glucose

Question 16

What hormone is mobilisation of liver glycogen stimulated by?

Answer 16

stimulated by the hormone, glucagon

Question 17

Mobilisation of liver glycogen provides enough glucose for the brain for…

Answer 17

1 day

Question 18

What breaks the 1-4 linkages in glucose

Answer 18

Glycogen phosphorylase

Question 19

what breaks 1-6 linkages in glycogen

Answer 19

Debranching enzyme

Question 20

Debranching enzyme
And Glycogen phosphorylase work together to..

Answer 20

Mobiles glucose for metabolism

Question 21

Answer 21

1. Glycogen phosphorlyse works with attaching an in-organic phosphate group onto a carbon of terminal glucose and cleaves the glycosidic bond between carbon 1 and 4 - producing glucose 1-P
2. Glucose-1 phosphate is then converted by mutate to glucose-6P
3. In the liver, NOT in muscle, only liver there is another enzymes called glucose-6-phosphatase

This glucose is for the Brian

Question 22

Gluconeogenesis
- where does it mainly occur?

Answer 22

Liver (also kidney cortex)

Question 23

Gluconeogenesis is the synthesis of glucose from:

Answer 23

lactate from muscle glycogen
alanine from muscle protein
glycerol from adipose tissue (TAG)

Question 24

What hormone is Gluconeogenesis stimulated by?

Answer 24

stimulated by glucagon

Question 25

Gluconeogenesis - what provides the energy required to do this?

Answer 25

fatty acid oxidation provides the energy required

Question 26

What is most of the glucose produced from gluconeogeneis used towards?

Answer 26

Brain

Question 27

What do lactate, Alanine and glycerol all have in common?

Answer 27

All 3 carbons in length - used in gluconeiogenesis by the liver

Question 28

Can Fatty acids (acetylCoA) be used to make glucose ?

Answer 28

Fatty acids (acetylCoA) cannot be used to make glucose B ut can via β-oxidation provide ATP and NADH for gluconeogenesis

Question 29

Big diagram

Answer 29

Remember the NADH part

Question 30

Where the liver gets heat it needs to make glucose form (gluconeogeneis)

Answer 30

Question 31

Starvation metabolism

Answer 31

Burn ca. 200 g of TAG per day; - if we get 40 kJ g -1 then: = 200 x 40 or 8000 kJ per day The glycerol released corresponds to about 20 g of glucose per day Brain needs about 120 g of glucose per day Proteolysis (alanine) to give 100 g of glucose per day corresponds to about 150 g of protein per day — this would deplete muscle reserves to critical in about 2 weeks! How did James last 43 days?

Question 32

How many kg of protein in our body? Where is it stored?

Answer 32

• 10 - 15 kg protein in body • BUT no specific storage proteins

Question 33

During starvation what happens to some protein?

Answer 33

must be degraded to amino acids to make glucose

Question 34

loss of too much protein causes…

Answer 34

structural and functional damage • protein must be conserved as much as possible

Question 35

Protein conservation system in human is specific to only —-

Answer 35

Humans

Question 36

Answer 36

Question 37

Clinical Research at Harvard — Metabolic Ward

Answer 37

Experiment — 6 weeks starvation New assays had been developed by the Krebb’s lab in Oxford Obese patient: Ms B 5’ 8’’; 280 pounds (127 kg) Measured Carotid artery entering and Jugular vein leaving and found 50 g ketone bodies used per day Hence providing 50% of the brain’s requirement

Question 38

Answer 38

Question 39

What are Ketone Bodies synthesised from and where are they synthesised?

Answer 39

• synthesised in the liver from fatty acids

Question 40

When are ketone bodies used?

Answer 40

• used by starving brain as energy source

Question 41

/

Answer 41

Human only adaptation

Question 42

Metabolic adaptations to starvation

Answer 42

• fatty acids can be used as a fuel by all aerobic tissues (except brain); essentially unlimited supply from TAGs • ketone bodies used by brain - Therefore, brain needs less glucose; now only about 50 g/day - Therefore, muscle degradation can slow down (not so many amino acids needed for gluconeogenesis) - Therefore, body can survive longer

Question 43

Glucose levels in blood over 40 days - Phases of starvation assessed from point of view of glucose metabolism

Answer 43

Question 44

How are you able to starve for so long

Answer 44

Fuel stores, gluconeogenesis and ketogenesis

Question 45

How does brain continue to function during starvation

Answer 45

Ketone bodies, glucose

Question 46

What happens to fat stores during starvation

Answer 46

Mobilised to fatty acids and glycerol

Question 47

What happens to muscle during starvation

Answer 47

Proteolysis to amino acids

Question 48

Did the energy from the chocolate bar help him survive?

Answer 48

About 1 h

Question 49

Question 50

Process of ketone body synthesis

Answer 50