Nutrition, Metabolism (Respiration+Fermentation), Body Temperature Regulation Flashcards
energy value of food
- kilocalories (kcal)
one calorie
- amount of heat energy needed to raise the temperature of one kilogram of water by 1 degree celcius
what is a nutrient?
- a substance in food that the body uses to promote normal growth, maintenance and repair
6 categories of nutrients
- carbohydrates, lipids, proteins
- vitamins, minerals
- water
major nutrients
- carbohydrates, lipids, proteins
What provide fibre? Why is fibre important?
- insoluble fibre like cellulose in plants and veggies; increases bulk of stool, facilitates defecation
- soluble fibres like pectin in apples and citrus fruits; reduces blood cholesterol level
Use of glucose in body
- carbohydrate monosaccharide
- used a fuel to produce ATP; especially neurons and RBCs
- fructose and galactose are converted to glucose first in liver
What happens to excess glucose?
- converted to glycogen or fat and stored
- example, in the liver
Uses of fats in body
- triglycerides = fuels for hepatocytes and skeletal muscles
- phospholipids = myelin sheaths and plasma membranes
- fatty deposits in adipose tissue: protective tissue, insulating layer, fuel
What lipid plays a role in smooth muscle contraction?
- prostaglandins (regulatory molecules formed from linoleic acid via arachidonic acid)
Uses of proteins in body
- structural materials: keratin in skin; collagen, elastin in connective tissues; muscle proteins
- enzymes and hormones
What is nitogen balance in body?
- body is in nitrogen balance when amount of nitrogen ingested in proteins equals the mount secreted in urine and feces
Hormonal controls on protein synthesis
- anabolic hormones accelerate it
- pituitary GH stimulate tissue growth
- sex hormones - growth spurt
Which hormones enhance protein breakdown and conversion of amino acids to glucose?
- glucocorticoids released during stress
What are vitamins?
- potent organic compunds needed in minute amounts for growth and good health
What are vitamins used for?
- not for energy or as building blocks
- helps body use nutrients for energy and building (carbo, proteins, fats)
What are coenzymes?
- vitamins that act with enzymes to accomplish a particular chemical task
vitamin B12 function in body
- coenzyme in nucleic acid metabolism
- maturation of RBCs
- function and development of brain and nerve cells
Vitamin B12 defeciency
- anemia: not enough healthy RBCs
- nervous system disorders
Vitamin for visuals
A
Extreme excess of vitamin A
- headache, irritation, vomiting, hair loss, “blurred vision”
Vitamin D deficiency
- bone deformities
Minerals in body
- seven
- Ca, P, K, S, Na, Cl, Mg
- phosphorus, potassium
- sulfur, sodium
- chlorine, calcium
- magnesium
Anabolism
- reaction that “bulid”
Catabolism
- reaction that “break down”
What is phosphorylation?
- attachment of phosphate (PO3) to a molecule or ion
- reverse is dephosphorylation
Where does glycolysis occur?
- the cytoplasm (cytosol)
Where do Krebs cycle and electron transport chain occur?
- in the mitochondria
3 metabolic phases of cellular respiratin
- glycolysis, Krebs cycle, electron transport chain
Summarize glycolysis
- in cytoplasm
- 10 steps
- anaerobic process
- glucose molecule broken down into 2 molecules of pyruvic acid
- small amount of ATP released
Summarize Citric Acid Cycle
- pyruvic acid enters mitochondrial matrix
- Krebs cycle decomposes it to carbon dioxide
- ATP released
Summarize electron transport chain
- “energy rich electrons” are picked up by coenzymes and transferred to the chain built into cristae membrane
- carries out “oxidative phosphorylation” = most ATP needed for cellular respiration is released here
What is glycogenesis?
- formation of glycogen from sugar (glucose)
- liver and skeletal muscle cells
Glycogenolysis
- breakdown of glycogen to glucose (in fact, glucose 1 phosphate and glycogen)
- happens when glucose levels drop
Gluconeogenesis
- process of forming glucose from noncarbohydrate molecules
- happens in liver
- when little glucose is available
- glycerol and amino acids converted to glucose
What is beta oxidation and where does it happen?
- happens in mitochondria
- initial phase of fatty acid oxidation
Net result of beta oxidation
- fatty acid chains are broken apart into 2 carbon acetic acid fragments
- coenzymes are reduced
- each acetic acid is fused to coenzyme A forming acetyl CoA
Lipogenesis
- conversion of fatty acids and glycerol into fats
- when ATP and glucose are excess
- acetyl CoA converted to triglyceride for storage
- reverse = lipolysis
Summarize carbohydrate metabolism
- converts galactose/fructose to glucose
- stores glucose as glycogen when glusoe is high (glycogenesis)
- glycogenolysis: break down of glycogen
- gluconeogenesis: converts aminoacids and glycerol to glucose
- converts glucose to fats for storage
Summarize fat metabolism
- liver: primary site for beta oxidation; breakdown of fatty acids to acetyl CoA
- converts excess acetyl CoA to ketone bodies
- forms lipoproteins for transport of fatty acids fats and choleterol in vlood
- synthesize cholesterol from acetyl CoA
Summarize protein metabolism
- converts amino acids to glucose for atp synthesis
-forms urea for removal of ammonia - forms most plasma proteins
What is radiation?
- loss of heat in form of infrared waves (thermal energy)
What is heat conduction?
- transfer heat through direct contact
What is heat convection?
- warm air expands and rises while cool air falls because denser
Processes that happen in liver
- beta oxidation (breakdown of fatty acid to two acetyl CoA)
- glycogenesis (formation of glycogen from glucose)
- gluconeogenesis (glycerol and amino acids to glucose)
- lipogenesis (conversion of fatty acids and glycerols into fats)
Where are glucocorticoids produced and what do they do?
- adrenal glands
- enhance gluconeogenesis in liver
Is glycolysis aerobic or anaerobic?
- anaerobic (doesn’t need oxygen)
Where does lipogenesis happen?
- liver and adipose tissue
Vitamin that aids in nucleic acid metabolism
- B12
