VCOM OMS-I Cell Bio Exam 2: Lecture 16 -- Metabolic States

energy balance

the relationship between energy intake and energy expenditure

essential fats

linoleic acid and a-linolenic acid

Eat more than you burn off

to gain weight

eat less than you burn off

lose weight

Essential Carbohydrates

none

linolenic acid ->

arachidonic acid (eicosanoid synthesis)

a-linolenic acid ->

eicosapentaenoic acid

eicosapentaenoic acid ->

docosahexaenoic acid

9 essential amino acids

M, I, L, K, V, F, W, T, H

how is fat stored?

as triglycerides in adipose tissue

how are carbohydrates stored?

as glycogen in muscles and liver, as triglycerides in adipose

how are amino acids stored?

amino acid pool and in muscles

fed state

when you start absorbing nutrients to when you stop absorbing; insulin is high and glucagon is low

fasting state

post-absorption until your next meal

starved state

after fasting for 3 or more days

what stimulates insulin release?

blood glucose

what are carbohydrates broken into?

monosaccharides

what are proteins broken into?

amino acids

what are lipids broken into?

emulsified into micelles

where are all nutrients carried to the liver?

portal vein

where are nutrients absorbed?

intestinal epithelium

where are fats carried?

lymphatic system before the liver

what is insulin's purpose?

detect glucose and tell the cells to intake

when is glucagon released?

When blood glucose levels are low

what does glucagon do?

tells cells to start using stored glycogen and glucose and release it into the blood

what happens to glucose after eating?

1. liver stores some as glycogen and uses some
2. brain and nerves eat as much as they can
3. RBC eat as much as they can
4. Muscles make glycogen stores and use it during exercise
5. adipose provide glycerol moiety to make fatty acids and to store them

what happens to lipoproteins after a meal?

1. chylomicrons are formed and transport triglycerides and cholesterol to the lymph, then blood, then tissues
2. muscles use fat first and the rest becomes adipose
3. remnant of chylomicron recycled by liver
4. VLDL formed in liver after triglycerides are made and carries these to adipose tissue and to peripheral systems

what happens to amino acids after a meal?

1. tissue uptakes and uses to make new amino acids or other metabolites like ATP, hormones, neurotransmitters, or heme
2. build muscles

normal concentration of glucose

80-100 mg/dL (peaks 1 hour after eating)

low glucose =

low insulin and high glucagon

high glucose =

high insulin and low glucagon

when is the body in its basal metabolic state?

12 hours after eating

how long does it take for glycogen to run out?

18-24 hours

when glycogen runs out, what occurs?

gluconeogenesis

ketone bodies

the product of the incomplete breakdown of fat when glucose is not available in the cells

what happens in starved state?

1. muscle quits making amino acids to preserve mass
2. ketone bodies take over as major food source
3. fat provides majority of energy
4. less urea produced to preserve metabolites