Food and Biomolecules

Biology

What are the functions of nutrients?

• Provides energy

• Provides raw materials for growth and repair of all bodily cells

• Aids the continuity of life

• Cell activity and metabolic reactions

Name the 6 common elements;

• Carbon

• Hydrogen

• Oxygen

• Nitrogen

• Phosphorus

• Sulfur

Name 5 dissolved salts;

• Magnesium

• Calcium

• Chlorine

• Sodium

• Potassium

Name 3 trace elements;

• Iron

• Copper

• Zinc

Define Biomolecule;

Chemicals made inside a living organism;

Proteins, Carbohydrates, Lipids, and Vitamins

What is the chemical composition of Carbohydrates

• Carbon

• Hydrogen

• Oxygen

What is the basic unit of carbohydrate

Glucose

What is the ratio of a carbohydrate

2 Hydrogen to 1 Oxygen - 2:1

What is the name of the solution used to test for reducing sugars

Benedicts solution

Does the test for reducing sugars need heat

yes

What colour does a positive reducing sugar test turn?

brick red

What is a monosaccharide

single sugar unit

Give 3 examples of a monosaccharide

• glucose

• fructose

• galactose

True of false; A monosaccharide is soluble in water

true

Define disaccharide

two monosaccharides joined together

Give three examples of a disaccharide

• maltose

• sucrose

• lactose

What is maltose composed of?

Glucose + Glucose

What is a polysaccharide?

consists of many sugar units combined

Name 3 polysaccharides

• Starch

• Glycogen

• Cellulose

What is Chitin

• Polysaccharide

• Builds walls of fungi and form skeleton of insects and crabs

Name 2 sources of starch

bread, potatoes

Is starch soluble or insoluble in water ?

Insoluble

What substance is used to test for starch

Iodine

What colour does a positive test for starch turn

blue / starch

What is glycogen?

• storage carbohydrate in animals

• found in the liver and muscles

What is another word for cellulose?

fibre

What is cellulose?

• cannot be digested easily by humans

• forms cell walls in plants

What is the structural role in of carbohydrates?

forms cell walls in plants

What is the metabolic role of carbohydrates?

ENERGY -

• Glucose provides energy when its broken down in respiration

• Glycogen stores energy in animals

• Starch stores energy in plants

What is the chemical composition of lipids?

• Carbon

• Hydrogen

• Oxygen

What is the difference between fats and oils at room temperature?

• Fats = solid at room temp

• Oils = Liquid at room temp

Name two sources of lipids?

• Butter

• Cheese

What is the structure of lipids?

TRIGLYCERIDES -

• 1 Glycerol & 3 fatty acids

What is a phospholipid?

A type of lipid in which one of the fatty acids are replaced by a phosphate molecule (phosphorylation)

What is the structural role of a lipid?

Phospholipids are a component in cell membranes

What is the metabolic role of lipids?

to release energy is respiration

How do you know if the test was positive in testing for fat?

brown paper remains translucent after drying

What is the chemical composition of proteins ( always )

• Carbon

• Hydrogen

• Oxygen

• Nitrogen

Name the 2 molecules that are SOMETIIMES found in proteins

• Phosphorus

• Sulphur

Name sources of protein

• Lean meat

• Chicken

What is the structure of proteins

• Folded

• Amino acids join together in a long chain to form a protein

• 20 different types of amino acids

• Peptide bonds form between amino acids

• Polypeptides consist of more than 20 amino acids

What determines a protein

the number and sequence of amino acids

What is a fibrous protein?

Have few or no foldings

Name 2 fibrous proteins and where they are found;

• Myosin - found in muscle

• Keratin - found in hair & nails

What are globular proteins?

Have many foldings

Name 2 globular proteins

• Enzymes - catalysts e.g amylase

• Hormones - chemical membranes e.g insulin

What is the structural role of proteins?

Keratin in hair and nails / Myosin in muscles

What is the metabolic role of proteins?

• Hormones - control body responses

• Enzymes - alter rate of reactions

What solution is used to test for protein?

Biuret solution (Sodium hydroxide & copper sulphate

How do you know protein was present when testing for proteins?

Turns purple

Define Vitamins

complex organic molecules that are needed in small amounts by the body to function properly.

Name the 2 water soluble vitamins

B & C

Name the fat soluble vitamins

A, D, E & K

Name a source of water soluble vitamins

citrus fruits

Name a source of fat soluble vitamins

fish oils

What is the deficiency of Vit c

scurvy

What is the deficiency in Vit D

Rickets (children)

Osteomalacia (Elderly people)