MCAT > Biochem Chapter 12 > Flashcards

Biochem Chapter 12 Flashcards

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1
Q

What does it mean by energy is conserved

A

It means it cannot be created or destroyed, only transformed from one form to another

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2
Q

There are 3 types of systems , waht are they and what they do

In terms of energy and matter transferable

A

Isolated: no energy or matter can be exchanged with surroundings

Closed: system can exchange energy but not matter with surroundings

Open: system can exchange energy and matter with surroundings

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3
Q

Biological systems are usually what systems

A

Open, exhcnage matter and energy

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4
Q

Biochemical studies are performed on the cellular/subcellular level so these are what systems usually

A

Closed

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5
Q

how can the energy in system be changed, through what and what

A

Heat transfer and work ( q+w) = U

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6
Q

Spontaneity of a reaction depends on

What’s the formula

A

Gibbs free energy = change in enthalpy - temperature x change in entropy

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7
Q

Is Gibbs free energy is negative, is it spontaneous

A

Spontaneous

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8
Q

If Gibbs free energy is positive, the reaction is spontaneous or no

A

Not spontaneous

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9
Q

Meaning of enthalpy delta H

A

Overall change in heat of a system during a reaction

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10
Q

Meaning of entropy delta S

A

Degree of energy dispersion in system

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11
Q

If enthalpy and entropy are both positive, what is the outcome of temperature in terms of spontaneity

A

Spontaneous at high temperatures

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12
Q

If enthalpy and entropy are both negative, what is the outcome of temperature in terms of spontaneity

A

Spontaneous at low temperatures

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13
Q

If enthalpy is positive and entropy is negative, what is the outcome of temperature in terms of spontaneity

A

No spontaneous at all temperatures

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14
Q

If enthalpy is negative and entropy is postiive, what is the outcome of temperature in terms of spontaneity

A

Spontaneous at all temperatures

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15
Q

Free energy at any condition

A

G = G*+RTlnQ

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16
Q

What does it mean when we say atp functions as. Mid level energy carrier

A

Releases moderate amount of free energy when hydrolysis d

Efficient without wasting too much energy

Inefficient because it is not stored, its not dense enough to be packed and stored

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17
Q

ATP is made through 2 types of phosphorylation

A

Substrate level phosphorylation and oxidative phosphorylation

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18
Q

ATP provides energy through what process (2)

A

Hydrolysis and coupling

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19
Q

ATP is most coupled with exergonic or endergonic reactions

A

Endergonic because atp is an exergonic process

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20
Q

What group transfers do atp do

A

Phosphorylation group

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21
Q

Oxidation and reduction

Which one is loosing electrons, which one is gaining electrons

A

Oxidation is loosing electrons

Reduction is gaining electrons

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22
Q

ATP hydrolysis yields about how much energy

A

30kj/mol

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23
Q

In reduction reaction of formula, the electrons are on teh left or right side of equation

A

Left

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24
Q

The most important electron carriers are what (2) to be electron carriers for redox reactions

What do they then turn into
And where do they go

A

NAD+ and FAD accept electrons to make NADH and FADH2, the reduced carriers deliver e- to ETC

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25
The dominant regulators of metabolism are What in fed state And what are the counter regulatory hormones at fasting state
Insulin at fed state Glucagon and epinephrine at fasting states
26
When does postprandial state (absorptive ) state occur
0-4 hours after eating
27
postprandial state (absorptive ) state Insulin and glucagon levels, which high which low
High insulin, low glucagon levels
28
Metabolic process In postprandial state (absorptive ) state
Anabolism and storage
29
What happens to glucose in postprandial state (absorptive ) state
There’s lots and is taken up by liver, adipose tissues and muscles
30
In postprandial state (absorptive ) state What synthesizes glycogen first and then converts it into what
Liver synthesizes glycogen first Converts excesss glucose to fatty acids and triglycerides
31
In muscles in postprandial state (absorptive ) state What does it do with glycogen and protein coming its way
Increase glycogen storage and protein synthesis
32
What happens to adipose tissue in postprandial state (absorptive ) state In terms of triacyglycerols
Synthesizes and stores
33
What is hte main purpose in postprandial state (absorptive ) state
Storing excess fuel for later use
34
Brain and red blood cels rely on what mainly for energy
Glucose
35
In Postabsorptive state (fasting ) state When is time frame
4-24 hours after eating
36
Hormone profile in Postabsorptive state (fasting ) state Insulin Glucagon and epinephrine levels
Insulin decreases, glucagon and epinephrine increase
37
Metabolic process for Postabsorptive state (fasting ) state is
Maintain blood glucose and mobilization
38
What happens in liver in Postabsorptive state (fasting ) state
Glycogenolysis ( breaks down stored glycogen into glucose to be released into blood stream ) and gluconeogenesis ( new glucose from non carb precursors like glycerol and lactate ) increases
39
What happens in adipose tissue in Postabsorptive state (fasting ) state
Increases lipolysis
40
What happens in muscles in Postabsorptive state (fasting ) state
Fatty acids use, atp production, muscle reduce demand for glucose
41
How does brain and red blood cells dependence change in Postabsorptive state (fasting ) state
Doesn’t, primarily still reliant on glucose
42
Overall goal in Postabsorptive state (fasting ) state
Preserve blood glucose
43
In prolonged fasting state (starvation) Time frame
More than 24 hours without food
44
In prolonged fasting state (starvation) hormone profile Glucagon and epinephrine
Very high for both
45
Metabolic processes in In prolonged fasting state (starvation) Changing of fuel source from what to what
Shift duel source from fat based metabolism to spare proteins
46
What are the last adaptable tissue that are least able to change its fuel source in periods of prolonged starvation
Anaerobic cells RBCs are least flexible on this time and glucose becomes unreliable at this period
47
What stage is there the greatest decrease in the circling concentration of insulin
Postabsorbtive Goes from high insulin, to low insulin, whereas counter regulatory hormones go up by so much
48
Insulin is a type of what hormone Is it water or fat soluble
Water soluble Peptide hormone
49
Water soluble Peptide hormones like insulin’s re above to quickly adjust their metabolic processes through __________ cascades
Secondary messenger cascades
50
Fat soluble amino acid derivative hormones like thyroids hormones and steroid hormones, like cortisol react quicker or slower long ranging effects by exerting regulatory actions at what level
Long ranging effects, transcriptional level
51
Insulin is produced by what cells
B-cells
52
What does insulin do - main job - stimulating uptake of what by what - promotes what anabolic processes
Lowers blood glucose by stimulating glucose uptake by cells and promoting anabolic processes like glycogen, fat and protein synthesis
53
Peptide hormones are derived from what and processed where
Precursor polypeptides, processed in golgi
54
Steroid hormones are derived from what and produced mainly in what
Cholesterol Gonads and adrenal cortex
55
Insulin independent tissues 5
BRAIN RBCS KIDNEY TUBULES INTESTINAL MUCOSA PACNREATIC BETA CELLS
56
Why is insulin a fed state hormone
it Lowers blood glucose by shiftingng body towards fuel storage and building pathways
57
Increasese glucose uptake in muslce and adipose tissues in done by GLUT what
4
58
Glucagon is produced by what cells
Alpha cells
59
What is glucagon for
Raising blood glucose levels by stimulating protein and fat degradation Increase glycogenolysis and Gluconeogenesis
60
Liver ketogenesis adn decreased lipogenesis is from insulin or glucagon
Glucagon
61
What are glucocorticoids for
They are responsible,for long term stress response
62
Cortisol is a type of
Glucocorticoids
63
What does cortisol do to blood glucose concentration what does it do to immmune system Protein synthesis acts on which level
Increases blood glucose concentration , inhibits immune system, reduces protein syntehsis, act on a transcriptional level
64
Glucocorticoids are released from
Adrenal cortex
65
Catecholamines are secreted by what
Adrenal medulla
66
Catecholamines examples
Epinephrine and norepinephrine
67
Glucocorticoids release is stimulated by what pituitary
ACTH
68
What does epinephrine and norepinephrine do to blood glucose
Promote glycogenolysis Increase heart rate and alter blood flow
69
Do thyroid hormones trigger metabolic rates after eating What’s do they set
No they se basal metabolic rate
70
2 primary thyroid hormones are
T3 and T4
71
T3 and T4 hormones are produced in what using what
Follicular cells By iodinating tyrosine
72
How does thyroids hormones increase metabolic rates i Cellular respiration Glucose use and fatty acid turnover Metabolic rates
Increase cellular respiration Increase glucose use and fatty acid turnover Increase glucose utilization Adjust speed of mobilization
73
Waht is the pathway for thyroid hormone
Hypothalamus Pituitary gland TSH Thyroid gland T3 T4
74
What vital sign abnormality might be expected in a a patient with a thyroid storm As in an extreme hyperthyroidism , high T3 and T4 levels What symptoms
High temperature High blood rate High temperature
75
When someone is fed, what does liver do What it store, what it make
Stores glucose as glycogen, makes fatty acids and VLDL
76
When someone is fasting waht does liver do What does it do
Glycogenolysis and Gluconeogenesis
77
Liver produces what during prolonged fasting
Ketone bodies
78
Skeletal muscles use what when a person is resting to power it
Glucose
79
When fasting,w hat does skeletal muscle use for energy
Fatty acids
80
When exercising, what do skeletal muscles use
Creating phosphate then glycolysis, then fatty acids
81
What doles skeletal muscle store for own use
Glycogen
82
Cardiac muscle prefers what as energy source at baseline
Fatty acids
83
When fasting, waht does cardiac muscle use ads fuel source
Ketone bodies
84
Adipose tissue when fed does that
Takes up glucose and fatty acids, and stores triglycerides
85
Adipose tissue when fasting does what
Release fatty acids via lipolysis
86
Brain primarily uses what as energy source
Glucose
87
Can brain use fatty acids as fuel
no
88
In prolonged fasting,w hat does brain use folr fuel
Ketone bodies
89
What doles RBC use as energy fuel ALWAYS
GLUCOSE
90
WHAT TYPE OF GLYCOLYSIS DOES RBCS RELY ON AND WHY WHAT CANT THEY DO
ANAEROBIC GLYCOLYSIS BECAUSE THEY DONT HAVE MITOCHONDRIA, CANT DO OXIDAITVE PHOSPYRLAITON
91
RBCS produce what
Lactate
92
What is integrative metabolism
Explains how body coordinators fuel use across tissues to maintain energy balance and body mass
93
Respiratory quotient (RQ) =
CO2 produced/ O2 consumed
94
If respiratory quotient is close to 1, what metabolism dominates
Carb metabolism
95
If respiratory quotient s closer to 0.7, waht metabolism is more
Fat metabolsim
96
Respiratory quotient tells us which is fuel is being mainly _____ Oxidised or reduced
Oxidised
97
Respiratory state is usually higher in which state and lower in which state
Higher in fed state Lower in fasting state
98
What is BMR basal metabolic rate
Energy required to maintain basic body function at rest
99
Does BMR increase or decrease with greater lean body mass
Increases
100
Which organ consumes most glucose compared to its percentage of body mass
Brain
101
If there is excess energy intake as compared to output, what happens to fat storage
Increases
102
What is the major contributor to long term changes in body mass
Lipids
103
What does ghrelin do Where is it released from
Increases hunger Stomach
104
What does leptin do Where is it release from
Decreases appetite Released from adipose tissue
105
What does Orexin do
Increases appetite and arousal
106
When a person exercises how does their respiratory quotient increase
Energy derived from glucose increases Exclusively carb metabolism Closer to 1
107
Is it easier to gain or lose wight and why
The threshold is lower for uncompensated eight gain than it is for weight loss. So its easier to surpass this threshold and gain weight than to lose wight
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