LC bio unit 1 - Food,

What do we need food for?

Energy,
growth of new cells,
repair and maintain of existing cells,
to make chemicals needed for cells reactions

What is a biomolecule?

molecules made inside a living thing

What are the 4 main bio molecules?

carbohydrates, proteins, lipids, vitamins

What elements make up carbohydrates?

carbon, hydrogen, oxygen

What is the general formula for carbohydrate?

Cx(H2O)y

Formula for glucose

C6H12O6

What are the 3 types of carbohydrates

monosaccharides, disaccharides, polysaccharides

Where are monosaccharides found? And examples?

Fruit. Glucose and fructose

characteristics of monosaccharides

single sugar unit
simple sugars
soluble in water
sweet to taste

Examples of disaccharides? And where they are found

Sucrose; sugar,
Maltose; germinating seeds,
Lactose; milk

characteristics of disaccharides?

2 monosaccharides joined together
soluble in water
sweet taste

examples of polysaccharides

starch, cellulose; plant cell walls, glycogen;

Characteristics of polysaccharides

many monosaccharides joined together
not soluble in water
do not taste sweet

What is metabolism?

all the chemical reactions in a living thing

What is the structural function for a carbohydrate?

Cellulose in the cell wall

What is the metabolic function for a carbohydrate?

energy

What does amylase break down?

starch

What is cellulose composed of?

many glucose molecules linked together

What are the benefits of cross bonding in cellulose ?

Very strong; this is why its used in the structure of cell walls
Very difficult to digest; why we use it as fibre/ roughage in our diet

Test for carbohydrates?reducing sugars and starch

(i) reducing sugars - benedicts solution
(i) starch - iodine

Structure of a lipid

Glycerol and three fatty acids. (trigilyicide)

Structure of a phospholipid

glycerol, 2 fatty acids, and a phosphate group

Structural role of lipids

store energy
insulate
form membranes

Metabolic role of lipids

release energy in respiration

Test for lipids

brown paper

Elements that make up proteins

carbon, hydrogen, oxygen, nitrogen

Structure of proteins

amino acids, peptides, poly peptides and protein

What ties amino acids together?

peptide bonds

What is a chain less than 20 amino acids called?

peptide

What is a chain more than 20 amino acids called?

polypeptide

What makes up a protein?

a chain of at least 200 amino acids

What are the 2 types of proteins?

fibrous and globular

Characteristics of fibrous proteins?

have little or no folding
form long fibers that are strong and tough
example: keratin in hair and nails

Characteristics of globular proteins?

have lots of folding
form round structures
Examples: enzymes

Structural role of proteins

form structures such as skin, nails, hair and muscle

Metabolic role of protein

enzymes
some hormones
antibodies

Test for protein

sodium hydroxide then copper sulfate

What vitamins do we need?

A, B, C, D, E, K

What is another name for vitamin c

ascorbic acid

is vit c water or fat soluble

water soluble

Sources? of vit c

veg and fresh fruit

Metabolic role? of vit c

forms connective tissue
bones and teeth
helps healing
immune system

Deficiency of vit c?

scurvy

is vit D water or fat soluble

fat soluble

Sources of vit D?

liver
fish oils
milk
made in skin - ultra violet rays

Metabolic role of vit D

helps absorb calcium for bones and teeth

deficiency of vit D

rickets in children
osteomalacia in adults

Why do animals need calcium?

for strong bones

Why do animals need iron?

to form hemoglobin in red blood cells

Why do plants need calcium?

to hold plant cells together

Why do plants need magnesium?

to make chlorophyll for photosynthesis

What percent of the body is made up of water?

60-70 %

Why do we need water?

Transport substances in blood or plants (good solvent)
Allows chemical reactions to take place
product of chemical reactions
good absorber of energy

What is an anabolic reaction?

Energy is taken in and used to convert small molecules to larger ones eg. photosynthesis

What is a catabolic reaction

larger molecules are broken down to smaller ones and energy is released eg. respiration