Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

GI > Biochemistry > Flashcards

Biochemistry Flashcards

1
Q

Definition of glycogenesis

A
  • synthesis of glycogen from glucose
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Define glycogenolysis

A
  • breakdown of glycogen to form glucose
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Define gluconeogenesis

A
  • new synthesis of glucose from metabolic precursors
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the main storage form of glucose in liver and muscle cells?

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

Glycogen is a ______

monosaccharide or polysaccharide?

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

what is the purpose of liver glycogen?

A
  • broken down between meals and released to maintain blood glucose levels for red blood cells and brain
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what is the purpose of muscle glycogen?

A
  • provides energy via glycolysis and the TCA during bursts of physical activity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what carbons are linked between glucose molecules in glycogen?

A
  • a 1-4 glycosidic links
  • branches by a 1-6 glycosidic links

*** exam

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is required to add glucose to an existing glycogen chain?

A
  • a glycogen primer [at least 4 glucose residues]
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the name of the protein a glycogen primer binds to?

A
  • glycogenin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the enzyme that converts glucose-1-phosphate to UDP-glucose?

A
  • UDP - glucose pyrophosphorylase
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Name of enzyme that converts UDP-glucose to glycogen?

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

What is UDP - glucose?

A
  • activated intermediates

- activated form of glucose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the role of glycogen synthase?

A
  • synthesis of glycogen from UDP-glucose
  • adds 1 glucose molecule to glycogen at a time
  • rate limiting enzyme
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the name of the enzyme that adds a branch to the 1-6 glycosidic branch in glycogen?

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

What is glycogenolysis catalysed by?

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

What are 3 precursors that can be used to generate glucose in gluconeogenesis?

A
  • lactate
  • amino acids
  • glycerol
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Gluconeogenesis is essentially the reverse of glycolysis

True or False

A

FALSE

  • if it was simply in reverse you would need to overcome chemically challenging energy steps
  • it employs 3 unique enzymes to over come these barriers
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the last intermediate in the TCA (4 carbon?)

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

How many liver enzymes are required in gluconeogenesis?

A
  • 3 enzymes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the role of PEP CK

PEP carboxykinase

A

rate limiting gluconeogenesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the cori cycle?

A
  • process of recovering lactate that is generated in the skeletal muscle
  • converted back to glucose, through the gluconeogenesis pathway
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

2 functions of insulin

A
  • burns of glucose –> glycolysis

- activates glycogen synthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what are fats important for?

A
  • as an energy source
  • essential fatty acids
  • for fat-soluble vitamins
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What are the 3 different lipid compounds?

A
  • simple lipids
  • compound lipids
  • steroids
26
Q

What is the structure of a triglycerides?

A
  • glycerol and 3 fatty acids
27
Q

Fatty acids are mainly bent structures

true/false?

A
  • FALSE

- mainly straight chains

28
Q

What is a cis group?

A
  • the 2 R groups are on the same side of the double bond

- cis –> think sisters (same side)

29
Q

What are the 3 main products of fat digestion?

A
  • glycerol
  • fatty acids
  • monoglycerides
30
Q

What are chylomicrons?

A
  • transport lipids absorbed from the intestine to adipose
31
Q

Define lipolysis?

A
  • breakdown of lipids

- by hormone sensitive lipases

32
Q

Where is fat stored?

A
  • in adipose tissue
33
Q

Fatty acids are converted to ________ in the cytoplasm

A
  • fatty acids oxidised to generate energy

- they are converted into CoA derivatives

34
Q

Name a rate limiting step for the process of energy conversion of lipids to be metabolised

A
  • carnitine shuttle
35
Q

What is the carnitine shuttle?

A
  • acyl- CoA transferred to carnitine

- facilitates acyl-CoA transport into the mitochondrial matrix

36
Q

What is a rate limiting precursor for the TCA?

A
  • Acetyl CoA
37
Q

What is the end product of beta oxidation?

A
  • Acetyl CoA
38
Q

Where are ketone bodies formed?

A
  • liver mitochondria
39
Q

When does the formation of ketone bodies usually occur?

A
  • in starvation and diabetes
40
Q

How many cycles of oxidation is involved in beta oxidation for an even saturated fat?

A

(C2n)

n-1 oxidation occurs for complete catalysis

41
Q

Malonyl CoA?

A
  • precursor of the synthesis of fatty acids

- lipid anabolism

42
Q

Define lipogenesis?

A
  • fatty acid synthesis
  • occurs mainly in the liver
  • mainly takes place during excess energy intake
43
Q

Where is Acetyl-CoA generated?

A
  • in the mitochondria
44
Q

What makes Acetyl-CoA, what enzyme?

A
  • pyruvate dehydrogenase complex
45
Q

Fatty acid synthase job?

A
  • catalyses synthesis of saturated long-chain fatty acids from malonyl-CoA, acetyl-CoA and NADPH
46
Q

4 Steps of fatty acid synthesis?

A
  • condensation
  • reduction
  • dehydration
  • reduction and release
47
Q

What carries the synthesised lipid after it is made?

A
  • acyl-carrier protein (ACP)
48
Q

What does insulin signal?

A
  • fed state

- stimulates storage of fuels and synthesis of proteins

49
Q

What does glucagon signal?

A
  • starved state
50
Q

What does epinephrine signal?

A
  • requirement for energy

- mobilise glycogen

51
Q

Where are the glycerols for triglycerides synthesised?

A
  • liver

- adipose tissue

52
Q

What is a major site of amino acid degradation?

A
  • liver
53
Q

What is protein turnover?

A
  • tightly regulated
  • different rates
  • damaged proteins have to be removed
54
Q

Nitrogen containing excretory molecules?

A
  • urea
  • uric acid
  • creatinine
  • ammonium ion
55
Q

Where is urea formed?

A
  • the liver
56
Q

What happens to glutamic acid during the formation of urea?

A
  • de-amination
57
Q

What are aminotransferases involved in?

A
  • moving the amino group from the a-amino acids to a a-keto acid
  • transamination
58
Q

Where does deamination/urea cycle occur?

A
  • in the liver
59
Q

What occurs during deamination?

A
  • amino group of glutamate is converted to free ammonium ion
60
Q

What is an end product of the urea cycle?

A
  • fumarate

- end-product in the cytosol

61
Q

3 different inherited disorders of amino acid degradation

A
  • alcaptonuria
  • maple syrup urine disease
  • phenylketonuria

GI (36 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions