Unit Exam 1 Flashcards
(110 cards)
1
Q
What is the primary source of energy for the body during fasting?
A
Liver glycogen
2
Q
What enzyme converts glucose-6-phosphate to glucose in the liver?
A
Glucose-6-phosphatase
3
Q
Which hormone stimulates glycogen synthesis in the liver?
A
Insulin
4
Q
What is the end product of glycolysis under anaerobic conditions?
A
Lactate
5
Q
What is the primary site of gluconeogenesis?
A
Liver
6
Q
What is the primary substrate for gluconeogenesis?
A
Lactate
7
Q
Which hormone stimulates glycogen breakdown in the liver?
A
Glucagon
8
Q
What is the final product of glycolysis under aerobic conditions?
A
Pyruvate
9
Q
Which enzyme converts pyruvate to acetyl-CoA in the mitochondria?
A
Pyruvate dehydrogenase
10
Q
Which enzyme converts glucose to glucose-6-phosphate in the liver?
A
Hexokinase
11
Q
What is the primary state of glucose-6-phosphate in the liver?
A
Glycolysis
12
Q
Which molecule allosterically activates pyruvate carboxylase in gluconeogenesis?
A
Acetyl-CoA
13
Q
What is the main storage form of carbohydrates in the body?
A
Glycogen
14
Q
Which enzyme converts glycogen to glucose-1-phosphate?
A
Glycogen phosphorylase
15
Q
What is the end product of the pentose phosphate pathway?
A
NADPH
16
Q
What is the key regulatory enzyme in glycogen synthesis?
A
Glycogen synthase
17
Q
What is the primary function of the Cori cycle?
A
Recycling of lactate produced by muscle cells
18
Q
Describe hybrid fibres
A
A mix of 2-3 of the muscle types.
They provide a functional continuum of fiber, phenotypes as they possess physiological properties that are intermediate to those of pure fiber types
19
Q
Why do slow twitch fibres appear red under a microscope versus the fast twitch, fibre that appear white?
A
This is because of the myoglobin storing oxygen in the muscles as slow twitch fibres have the highest oxidative capacity
20
Q
What is the primary function of carbohydrate metabolism?
A
To provide energy for the body
21
Q
Which hormone is responsible for lowering blood glucose levels?
A
Insulin
22
Q
What process converts glucose into pyruvate?
A
Glycolysis
23
Q
What is the end product of glycolysis?
A
Pyruvate
24
Q
What is the process called when glucose is converted into glycogen for storage?
A
Glycogenesis
25
Which enzyme catalyzes the rate-limiting step of glycogenolysis?
Glycogen phosphorylase
26
What is the main function of gluconeogenesis?
To produce glucose from non-carbohydrate sources
27
Where does gluconeogenesis mainly occur in the body?
Liver and kidneys
28
What is the process of converting amino acids into glucose?
Gluconeogenesis
29
Which hormone is responsible for increasing blood glucose levels?
Glucagon
30
What is the primary storage form of glucose in animals?
Glycogen
31
Which organ is responsible for maintaining blood glucose levels during fasting?
Liver
32
What is the process of breaking down glycogen into glucose?
Glycogenolysis
33
What is the key enzyme involved in the regulation of glycolysis and gluconeogenesis?
Phosphofructokinase-1
34
What is the Cori cycle?
The cycle of lactate produced by anaerobic glycolysis being converted back to glucose in the liver
35
What is the process of converting proteins or lipids into glucose?
Gluconeogenesis
36
What is the key regulatory enzyme in glycogenolysis?
Glycogen phosphorylase
37
Which enzyme converts glucose into glucose-6-phosphate in glycolysis?
Hexokinase
38
What is the process of converting pyruvate into glucose?
Gluconeogenesis
39
What is the primary fate of glucose-6-phosphate in glycolysis?
Further breakdown to produce energy or stored as glycogen
40
How do carbohydrates appear in the human body?
They are stored as a glucose
Blood glucose, liver, glycogen, and muscle glycogen
41
How does glucose travel through the blood?
It gets dissolved in blood plasma
42
How does glucose enter the cell?
Glucose enters the cell by GLUT 4 transporters. Insulin and calcium signalling are the main mechanisms. Glucose can only enter the cell when calcium is present.
43
Where is glucose metabolized during exercise?
During exercise, glucose is metabolized by glycolysis in the sarcoplasm
44
Outline characteristics of glycolysis
It occurs in the sarcoplasm, it involves 10 enzymatic reactions, glucose is metabolized into pyruvate
45
What does each cycle of glycolysis yield?
To ATP
To pyruvate
To NADH plus H
Two H2O
46
What happens to pyruvate after glycolysis?
In the sarcoplasm pyruvate is metabolized into lactate and in fast twitch, fiber, lactate dehydrogenase catalyzes the conversion of pyruvate into lactate. Lactate can then be transported in and out of cells by MCT transporters in lactate oxidation for removal from the body.
47
What are the two types of MCT transporters?
MCT 1 transports lactate into the cell
MCT 4 transports lactate out of the cell and into the extracellular space
48
What are the two types of lactate dehydrogenase?
Cytosolic lactate dehydrogenase, which favours the conversion of pyruvate to lactate
Mitochondrial lactate dehydrogenase, which favours the conversion of lactate to pyruvate
49
Outline characteristics of lactate oxidation
Lactate is either oxidized to pyruvate which enters mitochondria and is metallized through the tri carboxylic acid cycle, or lactate is converted to glucose through gluconeogenesis
50
Outline characteristics of pyruvate oxidation
Pyruvate is transported by mitochondrial pyruvate carriers across the mitochondrial membrane and into the mitochondrial matrix. Here, pyruvate oxidation metabolizes pyruvate into acetyl Co-A
51
What does each cycle of pyruvate oxidation yield?
One acetyl-CoA
One NADH plus H
One CO2
52
Each molecule of glucose produces how many molecules of pyruvate
Two, therefore, pyruvate oxidation has to occur twice for every molecule of glucose
53
State resting blood lactate level
0.5 to 2 mmol
54
Describe LT one
This is known as the aerobic threshold, this is when blood lactate concentrations rise above resting. This point the body is relying, mostly on oxidation of fatty acids.
55
In which cycle metabolizes lactate back into glucose
The Cori cycle
56
Describe LT two
LT two is known as the anaerobic threshold. this is when lactate reaches a point where your body makes more lactate disproportionately to your body is ability to clear it. During LT two, your body is almost exclusively relying on cards.
57
What is the primary source of energy for the body during low-intensity activities?
Fat
58
Which energy system is primarily used during high-intensity, short-duration activities like sprinting?
ATP-PCr system
59
During which energy system is lactic acid produced as a byproduct?
Anaerobic glycolysis
60
Which energy system requires oxygen to produce ATP?
Aerobic system
61
What is the primary fuel source for the aerobic energy system?
Carbohydrates
62
True or False: The ATP-PCr system is the fastest way to produce ATP.
True
63
Fill in the blank: The aerobic energy system is the most _______ and produces the most ATP.
Efficient
64
What is the main energy currency used by cells for various functions?
Adenosine triphosphate (ATP)
65
Which energy system is the dominant supplier of ATP during moderate-intensity activities lasting 1-3 minutes?
Anaerobic glycolysis
66
What is the byproduct of the ATP-PCr system?
Creatine phosphate
67
Which energy system utilizes stored glycogen as a fuel source?
Anaerobic glycolysis
68
What is the primary source of energy for the body during high-intensity activities lasting 3-10 seconds?
Creatine phosphate
69
What is the end product of anaerobic glycolysis?
Lactic acid
70
Which energy system is the most sustainable for long-duration activities like distance running?
Aerobic system
71
Fill in the blank: The _______ system is the primary source of energy during activities lasting 10-60 seconds.
ATP-PCr
72
What is the primary source of energy for the body during high-intensity activities lasting 10 seconds to 2 minutes?
Anaerobic glycolysis
73
Which energy system is the slowest to produce ATP but the most efficient for long-duration activities?
Aerobic system
74
True or False: The aerobic energy system can produce ATP without the presence of oxygen.
False
75
What is the primary energy system used during rest and low-intensity activities?
Aerobic system
76
Which energy system has the highest rate of ATP production but the lowest total ATP yield?
ATP-PCr system
77
List characteristics of the ATP – PC energy system
Anaerobic- alactic
Phosphocreatine substrate
Location is the sarcoplasm
It has the fastest rate of energy transfer
It has both the smallest energy contributions and substrate availability
78
Less characteristics of the glycolysis energy system
Anaerobic – lactic
Glucose substrates
Location is the sarcoplasm
Rate of energy transfer is fast
It has small energy contributions and substrate availability
79
List characteristics of oxidative phosphorylation energy system
Aerobic
Fatty acids lactate, and amino acid substrates
Location is the mitochondria
Slow rate of energy transfer
It has large energy contributions and substrate availability
80
What is the primary storage form of fat in the body?
Triglycerides
81
True or False: Fat metabolism involves the breakdown of triglycerides into fatty acids and glycerol.
True
82
What enzyme is responsible for breaking down triglycerides into fatty acids and glycerol?
Lipase
83
What is the process of converting fatty acids into acetyl-CoA called?
Beta-oxidation
84
Where does beta-oxidation of fatty acids take place in the cell?
Mitochondria
85
What molecule is produced when acetyl-CoA enters the citric acid cycle?
ATP
86
What is the end product of fatty acid metabolism in the citric acid cycle?
Carbon dioxide
87
What hormone stimulates the breakdown of fat in adipose tissue?
Epinephrine
88
What is the main function of brown adipose tissue in fat metabolism?
Thermogenesis
89
What is the main function of white adipose tissue in fat metabolism?
Energy storage
90
What is the term for the process of breaking down fat to release energy?
Catabolism
91
What molecule is used to transport fatty acids into the mitochondria for beta-oxidation?
Carnitine
92
What is the term for the process of synthesizing fat from non-lipid precursors?
Lipogenesis
93
What is the main site of lipogenesis in the body?
Liver
94
What is the primary role of the hormone glucagon in fat metabolism?
Promotes fat breakdown
95
What is the term for the process of converting excess amino acids into fat?
Tricarboxylic acid cycle
96
What is the primary function of acetyl-CoA in fat metabolism?
Energy production
97
What is the term for the process of breaking down fat for energy during fasting or starvation?
Ketogenesis
98
What is the term for the accumulation of fat in the liver?
Fatty liver disease
99
What is the main cause of fatty liver disease?
Excessive alcohol consumption
100
What is the term for the process of converting stored fat into energy?
Mobilization
101
What is the primary source of energy during prolonged fasting or starvation?
Fatty acids
102
What is the primary source of energy during high-intensity exercise?
Carbohydrates
103
What is the term for the process of converting non-carbohydrate sources into glucose for energy?
Gluconeogenesis
104
What is the term for the storage of fat in specialized cells called adipocytes?
Adipose tissue
105
How do free fatty acids enter the cell
At the muscle, free fatty acids disassociate from albumin and then get transported across the semi permeable membrane of muscle cells by fatty acid, translocate and plasma membrane fatty acid binding protein
106
How are fatty acids transported into the mitochondria?
Fatty acetyl KA is transported across the mitochondrial membranes by the carnitine shuttle by CPT one and CPT two
107
What does a cycle of beta oxidation yield?
One acetyl-CoA
OneFADH2
1NADH plus H
108
What does one cycle of the tri carboxylic acid cycle yield?
OneATP
3NADH plus H
OneFADH2
Two CO2
109
What does each round of oxidative phosphorylation produce?
13 ATP
Two H2O
110
Describe endogenous creatine synthesis
Creatine synthesis involves the kidneys and liver, endogenous creatine synthesis, requires glycine, arginine, and methionine
