Nutrition & Energy

Question 1

Carbohydrates (function, compostion, 3 types, stored, examples)

Answer 1

Main energy source for body. 4 calories energy/gram. Composition: carbon, hydrogen, oxygen C6H12O6. Monosaccharides (single molecule-glucose and frutose), disaccharides (2 sugar molecules-lactose), polysaccharides (10+ complex carbohydrate made of many single sugars-starch and cellulose). Daily-55% of person’s energy needs. Stored in liver and muscle tissues glycogen. (veggies, fruits, honey, nuts. sugars, milk. rice, potatoes, corn, wheat).

Question 2

Proteins (function, composition, 4 types, structure

Answer 2

Key building block of cells and perform a wide range of functions (hormones, energy source, movement-mitosis in muscles, structure-collagen and connective tissues, transporting oxygen (hemoglobin), builds and repairs. Composition: long chains of amino acids, 20 different types, humans can 12 amino acids. 8 amino acids buts be obtained from food sources (called essential amino acids) Primary structure-sequence of amino acids. Secondary-linked by hydrogen bonds. Tertiary-is formed when alpha helices and beta sheets are held together by weak interactions. Quaternary-more than 1 polypeptide chain. 10-30% should come from protein (meats, fish, beans, seeds) Structure depends on order of amino acids

Question 3

Protein Denaturing

Answer 3

shapes of proteins are critical to their proper functioning When the protein changes shape it becomes “denatured” Protein loses its ability to perform its specific function. Conditions that denature: heat, pH change, radiation, harsh chemicals

Question 4

Fats/lipids (function, composition, types, daily

Answer 4

concentrated energy source (helps absorb vitamins, component of the cell membrane, insulation). 3 fatty acid chains bonded to a glycerol molecule (tryglyceride). Unsaturated more than 1 bond, rigid: oils at room temp. Saturated 1 bond: solid at room temp, filled with hydrogen. Steroids: sex hormones & cholesterol. Daily energy needs, no more than 30% of energy intake (beef, butter, seeds, nuts). Cis vs trans fats, change texture and effect health