Download 5 Kingdoms of Life - Cellular

Biological Molecules – BZ 21 - 27
+ Water H2O
BZ 21 Biological Molecules
Water, carbohydrates, lipids and nucleic acids are the
molecules that make up all living things.
Start BZ 21
Structures of Biological Molecules
Construct a map of the terms only
BZ 21 - Water
Water is required for life to exist because it is:

Universal solvent – metabolic reactions occur in it easily.

Liquid at room temperature + low viscosity (flows easily
and animals can swim through it easily)

Thermally very stable and absorbs a lot of heat before
changing states.

Ice floats in water so the underlying water is insulated

High surface tension – forms droplets easily and flows
easily through narrow spaces – capillary action.

Colourless and allows high transmission of light.
Complete BZ 21
Do not draw
BZ 21 Ans
BZ 22 – Carbohydrates - CHO’s – saccharides
CHO’s are a family of organic (containing Carbon) molecules made up of
only carbon, hydrogen and oxygen.
created by photosynthesis in chloroplasts
•
consumed by mitochondria to release energy in cellular respiration
•
Monosaccharides - ribose, glucose, fructose
•
Disaccharides – Maltose, Lactose
•
Polysaccharide molecules
•
cellulose – wood/cell walls
•
starch – stored energy in plants,
•
chitin – arthropod exoskeletons, fungi cell walls
•
glycogen – stored energy for animals
BZ 22 Ans
BZ 23 - Lipids
Lipids are non-polar (non-charged), hydrophobic organic
molecules, that have many important biological functions.
 Characteristics
 Oily,
greasy or waxy.
 Relatively insoluble in water
 Higher concentration of energy than CHO’s or protein

Functions
 Protection of organs and insulation
 Energy storage
 Plasma membranes
 Hormones - steroids
BZ 23 Ans
BZ 24 – Nucleotides and Nucleic acids
Nucleotides are the building blocks of DNA and RNA. Nucleic acids are
long chains of nucleotides that store and transmit genetic information.
Nucleotide Structure

Base + sugar + phosphate group
 DNA
- Base + deoxyribose + phosphate group
 RNA
- Base + ribose + phosphate group
Functions of nucleotides
 Building
blocks of DNA or RNA (nucleic acids)
 Nucleotide
 ATP
derivatives
(adenosine tri-phosphate) – high energy bonds
DNA
BZ 24 Ans
DNA and RNA DNA – double helix
DNA replication - with animations BBC Bitesize, RNA - protein synthesis - BBC Bitesize
RNA – single helix
BZ 25 Amino Acids
Amino acids can be joined together to form polypeptides.
Proteins are made up of one of more polypeptide
molecules.

Characteristics

2 or more amino acids form peptides

Long chains of amino acids form proteins
Don’t Draw
Glutamine
BZ 25 Ans
BZ 26 – Globular proteins –
structure = function
Protein structure is related to its biological
function.
 Properties:
3
Don’t draw
Structural levels of Proteins – stop around 5 mins
 Soluble in water
 Geometry is critical to its function
 Folded

into a spherical shape
Functions:
 Catalytic - Enzymes
 Regulatory – Hormones
 Transport – Haemoglobin
 Protective - Immunoglobulins
BZ 26 Fibrous proteins – structure = function
Fibrous proteins

Properties:
Don’t draw
 Insoluble
 Tough
physically
 Parallel

in water
polypeptide chains
Functions:
 Structural
- collagen (connective
tissue), spider silk.
 Contractile
– myosin and actin
filaments in muscles.
BZ 26 Ans
BZ 27 Enzymes –
All about enzymes youtube
Enzymes are biological catalysts that speed up
reactions but are not consumed by them and
therefore can be re-used repeatedly.


They are effective in low concentrations

very specific (only catalyze one type of reaction)

deactivated or denatured by extremes of heat and pH
Properties:

The lock and key model (image over page)

Active site – specific shape (drugs used to kill
parasites can either block or alter the active site on
their enzymes)

Substrate – the specific chemical it works on

Fully re-usable
Explaining the shape of an enzyme graph

Heating a reaction makes the molecules move faster therefore
collide more often. More collisions in a given time means a
faster reaction rate.

Over heating the enzyme will denature it - alter its shape so it
no longer fits the substrate.

Changes in pH have similar effects.
Saliva contains Amylase, an enzyme that converts starches into
simple sugars. If you added amylase to a solution of starch, all of
the starch is broken down – regardless of the quantities - why?
BZ 27 Ans