Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

NME > Liver & Glucose Homeostasis > Flashcards

Liver & Glucose Homeostasis Flashcards

1
Q

Biomolecules as energy stores

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Fuel Metabolism: Energy for ATP synthesis derived from the oxidation of 3 main body fuels:

A
  • glucose stored as glycogen
  • long chain fatty acids stored as
    triacylglycerol
  • amino acids
  • obtained intermittently from meals yet
    required continuously
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What kind of proteins can enter the citric acid cycle?

A

Deaminated (remove nitrogen)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

2 requirements of fuel metabolism:

A

1) store fuels when abundant
2) release fuels in a controlled way during
the post-absorptive period, during
exercise or starvation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Phases of assimilation:

A

1) immediate absorptive events
2) post-absorptive events

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Phases of assimilation: Immediate absorptive state:

A
  • liver and adipose tissue mainly take up
    materials
  • glycogen
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Phases of assimilation: Post-absorptive state:

A
  • mobilisation of reserves of glycogen built up during feeding
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Functions of the liver (9):

A
  • store glycogen
  • break down glycogen
  • deaminates surplus amino acids and
    converts amino groups into ammonia and
    then urea
  • synthesise glucose from non-carb
    precursors
  • synthesise ketone bodies and secrete for
    fuel for other tissues
  • aid elimination of cholesterol from the
    body and synthesises bile salts from
    cholesterol
  • stores fat soluble vitamins ADEK
  • metabolism and elimination of drugs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Ketone bodies:

A
  • produced from fatty acid breakdown
  • acetoacetate
  • beta-hydroxybutyrate
  • acetone
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Liver and Ketone Bodies:

A
  • selfless
  • synthesise ketone bodies but can not
    utilise them as an energy source
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

hypoglycaemia

A

low plasma glucose concentration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Glucose metabolism

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Glucose metabolism and the Brain:

A
  • the brain is most vulnerable to
    hypoglycaemia as cerebral cells derive their
    energy predominantly from aerobic
    metabolism
  • Brain can not (3):
    • store glucose in significant amounts or
      synthesise glucose
    • metabolise substrates other than glucose
      or ketone bodies
    • extract sufficient glucose for their needs
      from extracellular fluids at low concs
      because glucose entry into the brain is
      not facilitated by hormones
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Why does RBCs need so much glucose?

A
  • no mitochondria present
  • can only use glycolysis no oxidative
    phosphorylation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Glycogenolysis

A

mobilisation of liver glycogen stores

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Gluconeogensis

A

glucose syntehsis in liver and kidneys from non-carb precursors eg amino acids, glycerol, lactate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Glycolysis

A

Oxidation of glucose by peripheral tissues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Mechanisms controlling blood glucose:

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Insulin primary mechanism

A

increase absorption of cells to glucose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Pancreas and Insulin Secretion:

A
  • blood glucose high -> high ATP in beta cells
    in the Islets of Langerhans
  • Closes K+ channels and depolarises
    membranes
  • Voltage gated Ca2+ channels open in
    response allowing Ca2+ to flow into the cell
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Alpha cells in the Islets of Langerhans (pancreas) secrete

A

glucagon (alphabetical both first)

22
Q

Beta cells in the Islets of Langerhans (pancreas) secrete

A

insulin (alphabetical both second)

23
Q

Blood glucose varies a lot throught the day and night due to changes in food intake.

True or False?

A

False
varies relatively little
controlled by fluctuations in circulating levels of insulin or glucose

24
Q

When dietary glucose intake is low,

A

glycogenolysis is high
gluconeogenesis is high before eating (mainly night)

25
Glucose is absorbed from the intestine for how many hours following a meal?
2-3 hours
26
Glycogen is degraded between meals and lasts for
12-24 hours
27
Glucose homeostasis
28
insulin stimulates
the entry of glucose into cells is the major and most important metabolic effect of insulin
29
How do polar molecules such as glucose enter cells, across a lipid membrane?
Antelded
30
Glucose enters cells by: - passive diffusion - facilitated diffusion - active transport
facilitated diffusion (down conc grad)
31
Family of glucose transporter proteins are structurally related but
encoded by different genes that are expressed in a tissue specific manner
32
Glucose transport into tissues: Glut 1:
- many tissues - erythorocytes - muscle - brain - kidney - placenta etc
33
Glucose transport into tissues: Glut 2:
- liver - pancreatic beta cells
34
Glucose transport into tissues:: Glut 3:
- brain
35
Glucose transport into tissues: Glut 4:
- skeletal muscle - adipose tissue ****insulin sensitive
36
Glucose transport into tissues: Glut 5:
- small intestine - (fructose not glucose transporter)
37
All cells express at least on isoform of glucose transporter proteins (Gluts). True or False?
True a certain level of glucose uptake is an absolute necessity
38
Glucose transporters
39
Insulin Regulation of Glucose Entry into Tissues:
- insulin binds to insulin receptor - causing auto-phosphorylation - changing conformation of insulin receptor on the inside of the cell - through cascade reactions results in the inhibition of lipolysis
40
Cellular effects of insulin:
Immediate effects: - increase in the rate of glucose uptake in muscle and adipocytes - modulation of activity of enzymes involved in glucose metabolism (occur in minutes, does not require protein synthesis, occurs at insulin 10-9 or -10 mols/L) Long lasting effects: - increased expression of liver enzymes that synthesize glycogen - increased expression of adipocyte enzymes that synthesize triacylglycerols - inhibits lipolysis in adipose tissues by inactivating hormon-sensitive lipase which mobilises fatty acids from TG stores - functions as a growth factor for some cells eg fibroblasts (occur over several hours, require continous exposure to insulin at 10-8 mol/L)
41
Pentose Phosphate Pathway
- cytosolic pathway in all cells - branches from glycolysis at G6P - Products: - ribose phosphate: synthesizes RNA/DNA - NADPH: biosynthesis, maintain redox balance of cell
42
Tissues involved in biosynthesis (liver, adipose) are rich in
PPP enzymes (pentose phosphate pathway)
43
in cells where biosynthetic processes are less active, PPP intermediates are
recycled back into glycolysis
44
Fate of glucose in muscle and heart
45
Fate of glucose in Liver
- Glut2 - stored as glycogen, glycolysis to form pyruvate and then acetyl CoA - some to produce ATP, excess acetyl CoA used for fat synthesis - some goes through PPP pentose phosphate pathway to form NADPH to support fat biosynthesis
46
Fate of Glucose in the Liver
47
Fate of glucose in the brain:
- Glut1 & Glut3 - aerobic metabolism to produce energy - some used in pentose phosphate pathway to provide NADPH for lipid synthesis
48
Fate of Glucose in Brain
49
Fate of Glucose in Adipose Tissue:
- Glut 4 - glycolysis to produce acetyl CoA to produce ATP or synthesise fats - some used for pentose phsophate pathway to produce NADPH also required for fatty acid synthesis
50
Fate of Glucose in Adipose tissue
51
Fate of Glucose in Main Body Tissues:
RBCs: Glut 1: glycolysis to lactate to produce energy - some used in pentose phosphate pathway to produce NADPH for the maintenance of reduce glutathione - RBCs do not have mitochondria and therefore can not oxidise glucose fully via the TCA cycle and the ETC - must rely on glycolysis of glucose alone for energy requirements
52
Fate of Glucose in Main Body Tissues

NME (52 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions