Chapter 8 - Nutrition and Metabolism Flashcards
Define Nutriants
a chemical substance that the body uses for growth, maintenane and repair
What are the 6 main nutriants?
carbs, lipids,protiens, water, minerals and vitamins
define metabolism?
sum of chemical reactions of the body
define anabolism
combining substances into more complex ones, uses more energy then produces
Define Catabolism
Breaks down complex organic compounds, releases energy.
what happens to carbohydrates after they are eaten?
poly and Disaccharides are catabolized into monosaccharide (glucose), fructose and galactose(changed into glucose shortly after absorptioN)
how does the body decide what happens with the glucose?
depends on the needs of the body cells.
what happens when the body requires ATP immediatly?
cells oxidize the glucose that is absorbed.
what happens if the glucose is not needed immediatly?
converted to glycogen for storage in liver cells and skeletal muscle fibers.
what happens when glucose is not needed immediately and the glycogen stores are full
the liver cells can transform the glucose into triglycerides for storage in adipose tissue.
how does glucose move into cells?
facilitated diffusion.
what are the 4 stages of glucose catabolism ( cellular respiration)?
1-Glycolysis
2-Formation of Acetyl Coenzyme A
3- Krebs cycle
4-Electron transport chain
explain Glycolysis
it is Anearobic metabolism ( doesnt require oxygen). Happens in the cytosol. breaks down 1 - 6carbon glucose molecule into 2pyruvic acids. which produces 2 ATP and 2 NADH, 2H
what happens to pyruvic acid when there is oxygen and when there is no oxygen?
in aerobic conditions, pyruvic acid is converted to acetyle Coenzyme A and enters the Krebs cyle. If it is in Anarobic conditions it is reduced to lactic acid.
Describe the formation of Coenzyme A
Pyruvic acid enters the mitochondria. It is then converted into a 2 carbon fragement (acetyle group) attaching to coenzyme to form Acetyle Coenzyme A
Describe the Kreb Cycle
energy transfers from Acetyle Coenzyme A to Nad and FAD forming NADH and FADH. it produces C02 and 1 ATP for each Acetyle Coenzyme A that enters. to get energy from NADH and FADH they go to the electron transport chain
Describe the Electron transport chain
NADH + H and FADH pass there high electrons through electron carriers and ATP is produced.
Which two processes make up Aerobic cellular respiration?
Kreb cyle and electron transport chain.
what is glycogenesis?
the conversion of glucose to glycogen for storage in the liver and skeletal muscles. its stimulated by insulin.
what is glycogenolysis?
the conversion of glycogen back into glucose. stimulated by glucagon and epi
what is Gluconeogenesis?
Formation of glucose from noncarbohydrate sources. occurs when liver is stimulated by cortisol and glucagon
explain some lipid Metabolism
Lipids can be oxidized to produce ATP. some stored in adipose tissue
what do triglycerides break into during lipolysis?
fatty acids and glycerol
how is glycerol broken down after lipolysis?
becomes glyceraldehyde 3- phosphate
