VET116 test 2 - nutrients and metabolism

what are nutrients

substances derived from food that are necessary to carry out normal body functions

what are the energy producing nutrients

carbs, fats, proteins

what are the non energy producing nutrients

water, vitamins, minerals

what is metabolism 

the sum of all biochemical events happening in the body

what is catabolism

breakdown of nutrients into smaller molecules to produce ATP

what is anabolism

use of nutrients and stored ATP to assemble larger molecules from the smaller components that are produced from catabolism

what are the 3 stages of catabolism

1. hydrolysis (digestion of nutrients) in the GI tract

2. anaerobic respiration in the cytoplasm of cells

3. Aerobic respiration in mitochondria of cells

describe the process of catabolism stage 1: hydrolysis

• hydro = water,  lysis = breakdown

• one molecule of water is used each time a nutrient is broken down

• breakdown of complex molecules to their component building blocks

describe the process of catabolism stage 2: anaerobic respiration

• anaerobic = no oxygen

• occurs in cytoplasm of cell

• nutrients are catabolized to produce acetyl-CoA and small amounts of ATP

describe the process of catabolism stage 3: aerobic respiration

• aerobic: requires oxygen

• acetyl-CoA enters the kreb cycle

• produces 36-38 ATP and CO2 at the end

• NOTE* if oxygen is scare, lactic acid is produced instead of ATP

describe the process of anabolism

• it requires ATP

• using the nutrients we just broke down, we build larger molecules

what are the end products of metabolism

ATP, water, and Carbon dioxide

what is a macronutrient

energy producing nutrients but before your body can use the energy from these macronutrients they must first be digested and then absorbed

what 3 forms do carbohydrates come in

• sugars - disaccharides and monosaccharides

• starches - polysaccharides

• cellulose - polysaccharides

what is glycolysis

• glycolysis occurs in the cytoplasm and it is anerobic

• glucose is broken down to form pyruvate which can then be used to make ATP

what happens if theres excess glucose

its converted to glycogen (stored in liver) or concerted to fat 

describe the steps of carbohydrate metabolism

• carbs are primarily broken down into glucose (monosaccaride) through hydrolysis

• glucose molecule now goes into glycolysis, occurs in cytoplasm where its broken down to pyruvate, doesnt require O2

• 2 pyruvate enters the kreb cycle and electron transport chain which occur in mitochondria. requires O2

• each glucose molecule produces 38 ATP

what is glucose 

-       Glucose is a monosaccharide, It is the simplest smallest dietary carb

-       It is metabolized within the cell to make energy (ATP) through glycolysis (cytoplasm) and cellular respiration (mitochondria)

OR

-       If there’s excess glucose its converted to glycogen (stored in liver) or converted to fat (stored in adipose tissue)

describe the steps of lipid metabolism

-       Lipids derived from the diet are first catabolized by hydrolysis in the GI tract to fatty acids and glycerol

-       They are then transported to the liver where the rest of lipid metabolism takes places

-       Glycerol and fatty acid chains are stored as fat or catabolized further for energy

-       Glycerol is further catabolized to acetyl-CoA & ATP

-       Fatty acid chains become fragmented and catabolized to Acetyl-CoA and ATP

o   Some are converted into ketones  

what happens during catabolism of protein by deamination of the amino acids

-       AA amino group (NH2) removed from the carbon chain and becomes ammonia molecule

-       Liver enzymes convert ammonia to urea which is eventually excreted in urine

-       The carbon chain is catabolized further to yield ATP

what happens during catabolism of protein by transamination of the amino acids

-       Amino group (NH2) is transferred to another carbon chain to from a diff AA

-       Occurs in mitochondria

-       Amino acid diffuses into cytoplasm where it becomes the building block of other proteins