exam II Flashcards
[lipids, protein, metabolism + exercise, energy expenditure]
1
Q
what elements are lipids composed of?
A
C, H, O
contain more carbon than carbs
2
Q
how many carbons do most common fatty acids have?
A
18
3
Q
medium chain fatty acids are how many carbons
A
6-12 carbons
4
Q
where does the MCFAs go?
A
DIRECTLY into capillaries
5
Q
how many carbons in LCFAs?
A
13 or more
6
Q
how are LCFAs transported?
A
through chylomicrons
7
Q
what make up the majority of fats in food?
A
triglycerides
8
Q
the shorter the carbon chain…
A
the softer the oil at room temperature
9
Q
which is more biologically preferential: cis or trans?
A
cis; bends, not as easily stackable
10
Q
advantages to hydrogenation of fats
A
- prolongs shelf life
2. making liquid vegetable oils more solid like shortening
11
Q
delta notation system
A
chain length & number, position of double bonds from CARBOXYL end
18:2[delta]^9, 12
12
Q
omega notation system
A
locates position of double bonds counted from METHYL end
18:2[omega]-6
13
Q
omega 3 & omega 6 structures
A
first points of unsaturation are at 3 and 6 carbons
14
Q
which are the two essential fatty acids?
A
linolenic & alpha-linolic acid
15
Q
how is 99% of body fat stored?
A
triglycerides
16
Q
what are phospholipids?
A
phosphate containing lipids
biologically involved in the cell membrane formation
17
Q
sphingolipids
A
build on amino acid sphingosine
insulators for nerve conduction, cellular recognition
18
Q
sterols have a ___ structure
A
ring
19
Q
cholesterol is a precursor for…
A
bile acids, sex hormones, adrenocortical hormones, vitamin D
20
Q
how does the liver play a role in fat digestion?
A
creation of bile for EMULSIFICATION
21
Q
how are fats absorbed?
A
intestinal lumen -> brush border membrane [enterocytes]
22
Q
where does chylomicron formation occur?
A
in enterocytes
23
Q
where are chylomicrons found?
A
within intestinal cells -> lymphatic system -> bloodstream
24
Q
function of low-density lipoproteins?
A
liver regulation
25
function of high-density lipoproteins?
remove cholesterol from cell
| anti-inflammatory properties
26
main function of lipoproteins?
transport lipids in the blood
27
trans-fatty acids and effect on cholesterol
raise LDL and lower HDL
28
how much does fat provide of the body's ongoing energy needs at rest?
60%
29
does cholesterol contain energy?
no
30
features of brown adipose tissue
high vascularity, abundant mitochondria, H+ pores in inner membranes formed by UCPs
31
nutritional recommendations of fatty acids
AIs for essential FAs
minimize trans fatty acids
unsaturated FAs should be primary source of dietary fats
32
what percentage of energy should come from fat?
20-35%
33
how much fat should the diet be capped at regarding saturated fat?
< 20 g/ 10% of total cals
34
what is the max amount of dietary cholesterol should a person consume in a day?
< 300 mg
35
which amino acids contain sulfur?
cysteine + methionine
36
primary structure of amino acids
linear amino acid sequence
37
secondary structure of AAs
coiling, folding, bending [hydrogen bonds]
| alpha-helices, beta-sheets
38
tertiary structure of AAs
overall total 3D confirmation of protein
39
quaternary structure of AAs
2+ polypeptide chains interacting
40
ESSENTIAL AMINO ACIDS
```
histidine
isoleucine
leucine
lysine
methionine
phenylalanine
therorinine
tryptophan
valine
```
41
conditionally essential amino acids
```
arginine
cysteine
glycine
glutamate
proline
tyrosine
```
42
sources of exogenous [dietary] protein sources
meat, poultry, fish, eggs, dairy, grains, grain products, legumes, seeds, nuts, vegetables
43
endogenous protein sources [from the body]
desquamated mucosal cells
| digestive enzymes + glycoproteins
44
end products of the digestion of proteins?
peptides + free AAs
45
pepsinogen
enzyme = HCl/pepsin
site of activity = stomach
end products = peptides
46
trypsinogen
enzyme = enteropeptidase/trypsin
site of activity = intestine
end products = smaller peptides, some free AAs
47
chymotrypsinogen
enzyme = trypsin
site of activity = intestine
end products = smaller peptides, some free AAs
48
how are the majority of AAs absorbed?
as peptides
49
how are amino acids catabolized?
removal of an amino group by transamination/deamination
50
what enzymes transfer amino groups?
aminotransferases
51
deamination is...
removal of an amino group
52
keto acid can serve as...
template if there is a nitrogen source available
53
which conenzyme is required for protein synthesis involving a keto acid?
vitamin B6
54
which two products are the products of deamination?
ammonia
| C structure without its amino group [often keto acid]
55
3 enzymes involved for the disposal of ammonia
1. glutamate dehydrogenase -> glutamate
2. glutamine synthetase -> glutamine
3. carbamoyl phosphate synthetase -> citrulline
56
if any of the enzymes involved in the production of ammonia are ineffective...
ammonia will NOT be produced
57
urea is made up of...
ammonia + CO2 + ammonia
water is removed
= urea
58
once amino group has been removed, the remaining molecule =
carbon skeleton/alpha-ketoacid
59
keto acids/carbon skeletons can be used to produce...
energy, glucose, ketone bodies, cholesterol, fatty acids
60
phenylalanine is converted to ___ by ___
tyrosine, phehydroxylase
61
PKU affects...
melanin + thyroid hormones
62
guthrie test...
detects increased phenylalanine
63
anabolism increases after...
ingestion of food
64
insulin is either anabolic or catabolic?
anabolic [promotes protein synthesis]
65
epi + cortisol effects on protein degradation?
release higher glucose-to-insulin ratio
66
enzymes involved in protein functions
```
dehydrogenases = remove/transfer H+ ions
kinases = add phosphate group
```
67
cartinine
fatty acid transport... mitochondria
68
how is alanine formed?
in muscle cells from transamination w/ glutamate + pyruvate
69
range of amount of protein needed per day per kg BW
0.8-1.0
70
to keep urea in solution...
the body needs h2o
71
is there currently an UL for protein?
no
72
digestibility percentage of [most animal proteins]
90-99%
73
eggs are...
100% digestible
74
which plant proteins are MORE digestible?
soy + legumes
75
which proteins are fast absorbed?
whey, soy, AA mixtures, prohydrolases
76
which proteins are slow absorbed?
casein
slower and more prolonged
AA [conc] helps reduce protein breakdown
77
what happens to excessive protein without training?
converted to fat
| muscle work builds muscle; protein does not
78
kwashiorkor
adequate energy intake w/o adequate protein intake
| edema owing due to loss of blood proteins
79
marasumus
wasting, emaciation
| chronic insufficiency of energy & protein
80
definition of metabolism
all chemical reactions and pathways that maintain life
81
which two compounds are present in every cell regardless of pathway?
pyruvate
| acetyl CoA
82
anabolic reactions...
require energy
83
catabolic reactions...
release energy
84
catabolic reactions ___ macronutrients
BREAKDOWN
85
anabolic reactions ___ macronutrients
SYNTHESIZE
86
which organ does every product go through?
the liver
87
CO2 does what in TCA cycle?
initiate fatty acid synthesis, gluconeogenesis
88
how are most enzymes controlled?
allosterically
89
role of malonyl CoA
allosteric control of cartinine acyltransferase;
first step of FA synthesis
associated with limitation of food intake
90
role of AMP activated protein kinase
controls both catabolic + anabolic pathway involving all macronutrients
++ activated by low energy
91
the TCA cycle is an AMPHIBOLIC pathway. what does that mean?
both anabolic + catabolic
92
what are the major fuels of the muscle?
fatty acids and glucose [ketone bodies if necessary]
93
GLUT-4 transporter is used in...
the muscle!
94
exclusive source of fuel for RBCs
glucose
95
where does excessive glucose go when liver's storage capacity is full?
FAs & triglycerols
96
fed state
lasts 3 hours after meal ingestion
97
post absorptive state
3-18 hours post meal
98
fasting state
18hours - 2 days without additional food intake
99
starvation state
> 2 days; full adaped state of deprivation
100
does the post-absorptive state contain ketone bodies?
no
101
when is a time period when the body is in the post absorptive state?
overnight fast; nearly all reserves of liver glycogen are depleated
102
what is the source of fuel for gluconeogenesis in the fasting state?
primarily AAs, glycerol, lactate
103
what physiological change occurs in the starvation state?
LIPOLYSIS, FAs used to a greater extent, increase in ketone body synthesis
104
which hormones promote anabolic reactions [energy storage]
insulin
105
which hormones promote catabolic reactions [energy utilization]
glucagon, epinephrine, cortisol
106
which hormones promote both anabolic AND catabolic reactions depending on the target tissue?
growth hormone
107
insulin role in metabolism
critical in fed state; removing glucose to prevent hyperglycemia
increases glycogen synthesis in liver + skeletal muscle; stimulates FA synthesis
108
glucagon role in metabolism
prominent in NONFED states
109
epinephrine role in metabolism
inhibits insulin secretion, stimulates glycogen breakdown, inhibits glycogen synthesis
110
cortisol role in metabolism
responds in decrease in BG levels
111
growth hormone role in metabolism
stimulates lipolysis + release of FAs from visceral adipose tissue
increase triglyceride uptake in liver
112
function of muscle in metabolism
release of more glucose, FAs, increase in gluconeogensis, glycogenolysis, lipolysis NO GLYCOLYSIS
113
pathway of the anaerobic [lactic acid system]
glucose -> pyruvate -> lactate
114
pathway of aerobic [oxidative system]
glucose -> pyruvate -> acetyl CoA
115
how much ATP produced in aerobic activity?
38 ATP + CO2 + h2o
116
how much ATP produced in anaerobic activity?
2 ATP + lactic acid
117
VO2 max
measurement of max amount of o2 that an individual can utilize during intense, maximum exercise
118
how to correct muscle fatigue?
reduce exercise + intensity OR consume glucose
119
what percentage of energy expenditure does the thermic effect of food account for?
5-30%
120
what does direct calorimetry measure?
energy expenditure:
| highly expensive, conditions have to be "perfect"
121
indirect calorimetry
heat release calculated indirectly by measuring the consumption of OXYGEN
122
respiratory quotient
ratio of CO2 produced relative to O2 consumed
123
which macronutrient has the highest RQ?
carbohydrates
124
which macronutrient has the lowest RQ?
protein
125
range of RQ for "ordinary person's" diet?
0.7-1.0
126
max HR is ___ of VO2 max
80%
127
how to calculate max HR?
220-age
128
basal metabolism:
energy needed to maintain life
| when body is at complete digestive, physical, and emotional rest
129
basal metabolic rate
very complicated lab conditions; use resting metabolic rate > basal
130
how many hours does RMR require?
3 hours
131
which patients do Harris-Benedict equations support?
patients with liver disease
132
which sex has higher RMRs?
men > women
133
male formula for mifflin- st jeor equation
[10 x weight] + [6.25 x height] - [5 x age] + 5
134
female formula for mifflin-st jeor equation
[10 x weight] + [6.25 x height] - [5 x age] - 161
135
what influence energy expenditure?
duration, intensity, frequency of activity
136
PALs numbers
sedentary = 1.15
low active = 1.50
active = 1.75
very active = 2.20
137
which macronutrient has the greater thermic effect?
protein
138
what is the range of the body's biological temperature to function optimally?
98.2-98.6
139
ideal body weight [hamwi method] for males
106 lbs for first 5f + 6 lbs for each additional inch
140
ideal BW [hamwi method] for females
100 lbs for first 5 ft + 5 lbs for each additional inch
141
BMI categories
underweight = < 18.5
normal/healthy weight = 18.5-24.9
overweight = 25.0-29.9
obese = > 30
142
what age range is pediatric BMI calculated?
2-20
143
what is "healthy" weight for pediatric BMI?
between 5th and 85th perecentile
