Biology CT3 revision

What elements are in Carbohydrates?

Carbon, Hydrogen, and oxygen

What elements are in Proteins?

Carbon, hydrogen, oxygen, and nitrogen

What elements are in Lipids?

Carbon, hydrogen, oxygen

Carbohydrates

Biological molecules that give energy

Proteins

Biological molecules that build and repair the body

Lipids

Biological molecules that store energy for later

Carbohydrate structure

monosaccharide - one basic unit, disaccharide - two basic units, or polysaccharide - multiple basic units. Hexagon shaped with atoms at each point.

Proteins structure

Amino acids linked by peptide bonds

Lipids structure

glycerol and three fatty acids

example of a carbohydrate monosaccharide

glucose

example of a carbohydrate disaccharide

sucrose

example of a carbohydrate polysaccharide

Starch

Food test for glucose - what’s it for, what do you use, and results

Used for reducing sugar - carbohydrate mono or disaccharide. You use Benedict’s reagent. Results: Blue - no sugars, green - trace of sugars, yellow - low sugars, orange - moderate sugars, red - high sugars. You heat the solution at 90 degrees for the result.

Food test for starch - what’s it for, what do you use, and results

Used for carbohydrate - polysaccharide. You use Iodine. Results: orange/yellow/brown - negative, blue - positive.

Food test for Protein - what do you use, and results

You use biuret’s reagent. Results: Blue - negative, Purple/lilac - positive

Food test for fat - what’s it for, what do you use, and results

Its used for lipids. You use Ethanol and water - its called the emulsion test. Results: Clear - negative, Cloudy white emulsion - positive.

What is diffusion

Diffusion is the net movement of molecules/ions down a concentration gradient, from a region of high concentration to a region of low concentration

What is concentration

Concentration is the number of particles within a given volume