LC Biology- Food

INCLUDES EXAM QUESTIONS

describe the structure of a phospholipid

consists of glycerol and 2 fatty acids

one part of the cell other than the cell membrane where you would find a phosphate bilayer

mitochondria or vacuole

what biomolecular/Sub units are protein made of?

amino acids linked by peptide bonds.

what class of biomolecules is composed of nucleotides

nucleic acids

the general formula for carbohydrates

Cx(H2O)y

structural role of lipids in cells

cell membrane

metabolic role of lipids

hormone production, energy storage

elements present in food as dissolved salts

potassium, sodium,chlorine, calcium,magnesium

method of testing for protein:

1. make up biuret solution

2. pour some milk into biuret solution

3. pour water into separate biuret solution

4. observe colour change milk: blue→ purple

method of testing for lipids:

1. rub some oil onto brown paper and leave dry

2. pour water (control) on brown paper and leave dry

3. analyse observation

method of testing for starch:

1. iodine on bread

2. observe colour change brown to black

method of testing for reducing sugar:

1. reducing sugar is dissolved and added to test tube with benedicts solution

2. benedicts solution added with water in seperate test tube (control)

3. observe colour change blue to brick red

smallest unit of a carbohydrate

monosaccaride

monosaccaride

contains 1 sugar unit, maltose

disaccaride

contains 2 sugar units, glugose

polysaccharide

cellulose

metabolic role of protein

enzymes

2:1 ratio in carbs

hydrogen:oxygen