Chapter 25 - Nutrition Flashcards
healthy
proteins, carbs, fats, vitamins and minerals, salt
metabolism
Sum of all chemical and physical changes that occur in body tissues
catabolism
catabolic reactions
–Converts large molecules into smaller ones
–Breakdown of organic substrates releases energy to make ATP
anabolism
functions of anabolism?
anabolic reactions
–Converts small molecules into larger ones
–Synthesis of new organic compounds is an “uphill”process that forms new chemical bonds
Functions of anabolism
–Perform repairs
–Store nutrient reserves
nutrient pool
All available nutrient molecules distributed in blood
brain cant go without
5 seconds of sugar
where do we keep glycogen?
liver (they release it), muscle (they store it)
carbohydrates
where do we store proteins?
muscle
amino acids
where do we store fats?
skin, visceral fat, liver
fatty acids + glycerol
nutrient reserves
triglycerides
- Most abundant storage lipids
* fatty acids
glycogen
- Most abundant storage carbohydrate
* A branched chain of glucose molecules
proteins
•Most abundant organic components in body
25 year old male what is the proportions?
muscle
fat
bone mass
38
15
27
25 year old female what is the proportions?
muscle
fat
bone mass
32
25
24
females have higher fats bc
males have more muscle bc
of estrogen and pregnancy
of testosterone
oxidation
loss of H or electrons. E donor is oxidized
reduction
gain of H or electrons. E recipient is reduced
electron transport chain
- in mitochondria
- e passed though series of oxidation-reduction reactions
- ultimately transferred to oxygen
coenzymes
FAD and NAD
they either accept or remove H atoms
cellular
Glucose + oxygen –> carbon dioxide + water
- Involves glycolysis, citric acid cycle, and electron transport chain
- 1 molecule of glucose= net gain of 30–32 molecules ATP
glycolysis steps
breaks down into two 3 carbon molecules of pyruvic acid
creates glucose-6-phosphate
aerobic metabolism
–in mitochondria
–Requires oxygen
–Krebs cycle, generates ATP
oxidative phosphorylation
happens in mitochondria
for most cells generating ATP is the reaction pathway that
starts with glucose, and ends with CO2 and water
gluconeogenesis
making glucose from noncarbohydrate molecules
–Glucose is stored as glycogen in liver and skeletal muscle
how many carbons does one single AA have?
at least 2
only tissue that can release glucose
is liver. liver can increase glucose levels.
Lipid catabolism (lipolysis)
breaks lipids down. Converted to pyruvate
•Channeled directly into citric acid cycle
Hydrolysis splits triglyceride into component parts
- 1 molecule of glycerol
* 3 fatty acid molecules
Enzymes in cytosol convert glycerol to pyruvate
Pyruvate is converted to acetyl-CoA and enters citric acid cycle
when sugar levels go down
we are burning fatty acids
carbs
source of energy, but it has to be at a specific level (insulin and glucagon). where we getting energy from if we don’t eat? fatty acids.
cells gain 120 ATP from breakdown of
one 18 carbon fatty acid molecule
lipids are not
soluble in water
- special transport mechanisms
- most lipids circulate through bloodstream as lipoproteins
free fatty acid (FFA)
– diffuse easily across plasma membranes
–In blood, bound to albumin (most abundant plasma protein)
•Those not used in making of triglycerides that diffuse from intestinal epithelium
lipoproteins
–Lipid–protein complexes
•Low-density lipoproteins (LDLs)—“bad cholesterol”
•High-density lipoproteins (HDLs)—“good cholesterol”
resting skeletal muscles absorb
fatty acids and break them down for atp production or storage as glycogen
major cause of heart attacks
LDL
when you have high levels of HDL
returns cholesterol to liver
LDL’s extract
cholesterol and uses it in various ways
normal levels of
HDL
LDL
> 350
< 100
body makes how many proteins?
100,000 - 140,000 proteins
vitamin B6
removal of amino group. urea cycle
when you break down proteins you get
ammonium ions. difficult to break down.
cortisol levels peak around
8 or 9 am. little peak at lunch.
if you have a lot of cortisol you are
fat and stressed
five metabolic tissues
–Liver –Adipose tissue –Skeletal muscle –Nervous tissue –Other peripheral tissues
Adipocytes are located in many areas
- Areolar tissue
- Mesenteries
- Red and yellow bone marrows
- Epicardium
- Around eyes and kidneys
skeletal muscles uses
glycogen reserves
other peripheral tissues
follows instructions from endocrine system
absorptive state
- Period following a meal
* Lasts about four hours
Postabsorptive state
•Normal blood glucose levels
•Body relies on internal energy reserves
•Most cells break down lipids or amino acids
–Preserving glucose for use by nervous tissue
leptin
released by adipose tissues during absorptive state
-suppress appetite
ghrelin
released by empty stomach, stimulates appetite
CCK
released by pancreas
suppress appetite
leptin, ghrelin, CCK, and regulation of energy intake
emotional state, its personal
cis unsat fat
easier to break down
trans unsat fat
bad, harder to break down, more stable, not natural
false
fat =
unsat =
bad
bad
