exam 3 Flashcards
4 main pathways in energy metabolism
- glycolysis
- pyruvate–>acetyl CoA
- citric acid cycle (Kreb’s cycle)
- electron transport chain
Glycolysis occurs occurs in the ___ of the cell
cytoplasm
what needs to be present for pyruvate to enter Kreb’s cycle
CoA
produced when oxygen is not present with pyruvate
lactic acid
produced when pyruvate IS IN PRESENCE of oxygen
acetyl CoA
pyruvate joins with CoA
Krebs Cycle
after glycolysis, where does the next step occur?
mitochondria
what part of the cell produces the most ATP?
electron transport chain
what forms citric acid?
2-C acetyl CoA joins with 4-C axaloacetate
last step in energy production
electron transport chain
what is produced from 1 molecule of glucose?
36-38 ATP molecules
waste products of metabolism
CO2, H20, heat
what is the “Cori cycle?”
pyruvate forms lactic acid when oxygen is not available
what form of energy does NADH and FADH2 transport?
high energy hydrogen electrons
where is the energy from high energy hydrogen electrons transported?
to the electron transport chain
how is energy produced by triglycerides?
beta-oxidation
split into glycerol and 3 fatty acids
process by which fatty acid chains are “clipped” by 2 C at a time
beta-oxidation
a fatty acid can produce ___ ATP than carbs and proteins
more
substance necessary to carry fatty acids into the mitochondria for energy metabolism
carnitine
without carbs, what does acetyl CoA form?
ketones
process through which energy is made from protein
deamination
gluconeogenesis
making new glucose
glycogenesis
making glycogen
glycogenolysis
removing glucose from glycogen stores
lypogenesis
making lipids
result of burning fat for energy when carbs are not available
buildup of toxic ketones in body
hours of fuel available from carbohydrates during fasting
12
when a person in is negative energy balance
anorexia nervosa, illness, preferred weight loss
when a person is in positive energy balance
infancy, childhood, adolescence, pregnancy, overweight
kcals in pound of adipose tissue
3500
hypertrophic growth of fat cells
increase in size (up to 20x)
hyperplastic growth of fat cells
increase in number when cells are full
subcutaneous adipose tissue
found under skin, mostly in the thighs, hips, and buttocks
hypothalamus
part of brain that controls hunger and satiety
ways that make the body respond to hunger or satiety
gastric distention
GI hormones
stress and other emotions
circulating nutrient levels (glucose, amino acids, fatty acids)
TEE
total energy expenditures
of all the energy we take in, where is it used?
components of TEE
basal metabolism*** most used
physical activity–>only one we have control of
thermic effect of food (TEF)
BMI for underweight, normal, overweight, obese
underweight: 30
criticisms of using BMI
- doesn’t consider muscle
- doesn’t show all aspects of health
- doesn’t show fat distribution
- hydration level changes weight
% of U.S. adults considered to be obese
35
hunger
physiological drive to consume food
satiety
satiety physiological response to having eaten enough; feel
visceral adipose tissue
found between internal organs in abdomen
energy nutrients used to make energy
proteins, fats, carbs
metabolic fuel
glucose, fatty acids and amino acids
Catabolic
Catabolic pathway that releases energy through the breakdown of complex molecules to simpler ones
what does the citric acid cycle end with
oxaloacetate
proteolysis is the break down of
proteins
what is the second step of proteolysis
transamination and deamination
what is the second step of glycogenolysis
glycolysis
what is the second step of lipolysis
beta-oxidation
lipolysis is the break down of
fats
what starts the citric acid cycle
Acetyl CoA
When glucose occurs in the liver and pyruvate has to form lactate due to limited (or no) oxygen
Cori Cycle
Anabolic pathway and when we make new glucose from pyruvate, lactate, glycerol and amino acids
Gluconeogenesis
Amphibolic
anabolic and catabolic can use both these pathways
When is the most ATP made
lipolysis
36-38 ATP is made when
glycogenolysis
When does Metabolism happen
all of the time
When there is inadequate amount of glucose in your body
ketotones
What is positive energy balance
when you gain weight
What is negative energy balance
when you lose weight
What is the most dangerous Adipose Tissue
Visceral
What is Transamination
Transfer of amino group
Deamination
Using amino acid as energy to get out
how it cellular metabolism regulated
by hormones
whats the first priority of fasting
provide glucose for red blood cells, brain and central nervous system
whats the second priority of fasting
maintain muscle mass
resting energy expenditure (REE)
resting metabolism is expressed over a 24-hour day
