Biological Molecules 2.1.2

Not finished. Need points ,g,h

Water with hydrogen bonds image

What is it called when one side is positive and the other side is negative

Di-pole effect, oxygen = negaitve

Describe the structure of a water mol.

Water is a polar molecule

Hydrogen bonds form when a slightly negative oxygen of one molecule comes close to a slightly positively charged hydrogen on another molecule

How would you get 3 marks for describe the structure of a water mol. without writing the whole thing out

DRAW IT

Label the hydrogen bonds and the delta -/+

Draw and and label h+ bond

WRITE water is a polar molecule

What are the properties of water

Has a high boiling point

Ice is less dense than water

Cohesion

Adhesion

Water acts as a solvent

Transport medium

Evaporates

High specific heat capacity

High latent heat of vaporisation

Capillary action

Why is a high boiling point of water important

A lot of energy is needed to break the many hydrogen bonds

Examples of water with a high boiling point in nature

Stable water temperature for aquatic animals

Less energy spent on temp control

Why is ice being less dense than water important

Creates an insulating barrier

Water below doesn’t freeze

Allowing organisms to move under water

Examples of ice being less dense than water in nature

Habitat for animals like polar bears on top of ice

Fish can move under the water

Why is cohesion in water important

Cohesion = hydrogen bonding in water

Examples of cohesion in nature

Creates high surface tension for insects like water skaters to walk on

Water moving through the xylem

Why is adhesion in water important

Adhesion = waters attraction to other molecules/ surfaces

Examples of adhesion in nature

Water moving through the xylem

Why is water acting as a solvent important

Allows mineral ions to be transported around plants and animals

Example of water acting as a solvent in nature

Substances dissolving in the blood stream

Why is water being a transport medium important

Allows transport of soluble substances

Example of water being a transport medium in nature

Transporting substances around the body in the blood or around a plant

Why is evaporation of water important

Evaporation is a cooling mechanisms - the evaporating water takes heat away from the body

Example of evaporation of water in nature

Sweating in mammals or panting in dogs to cool them down

Why is high specific heat capacity of water important

Takes a lot of energy to heat up water by one degree

Example of high SHC of water in nature

A stable temperature

Enzyme can work at optimum temp

Gases remain soluble for aquatic organisms

Why is high latent heat of vaporisation of water important

Takes a lot of energy to change water from a liquid to a gas form

Example of high LHV of water in nature

Metabolic reations

Why is capillary action of water important

Allows water to move up narrow vessels

Example of capillary action of water in nature

Water moving up the xylem in plants

Condensation reaction

Covalent bond formed

Water mol. is removed

Hydrolysis reaction

(hyBROlysis)(hydro flask = water in the bottle)

Covalent bond broken

Water mol. is added

Elements in carbohydrates

Carbon

Hydrogen

Oxygen

Elements in lipids

Carbon

Hydrogen

Oxygen

Elements in proteins

Carbon

Hydrogen

Oxygen

Nitrogen

Sulfur

Elements in nucleic acids

Carbon

Hydrogen

Oxygen

Nitrogen

Phosphate

What is a monomer (General definition)

Single unit

What is a polymer (General definition)

Several monomers joined together

Monosaccharides

One unit of sugar

Simple sugars that form the monomer units

Disaccharides

Two monosaccharide mol. joined together

Polysaccharide

More than two monosaccharides joined together

e.g Starch

Two main monomers with carbohydrates

Alpha and Beta glucose

Alpha glucose diagram

NEEDS NUMBERS

Beta glucose diagram

NEEDS NUMBERS

Key difference between alpha and beta glucose

In alpha glucose - carbon 1, H is above while the OH is below

In beta glucose - carbon 1, OH is above and the H is below

Way to remember the difference between Alpha and Beta glucose

Glucose being a hexose sugar definition

6 carbon atoms

Glucose being reducing sugar meaning

When its in solution it can reduce other chemicals

Pentose sugar meaning and example

Has 5 carbons

Ribose - C₅H₁₀O₅

Found in RNA

Disaccharide bond image (alpha)

Alpha glycosidic bond between Carbon 1- 4

Covalent bond in carbohydrates

Glycosidic bond

When beta glucose bond

Orientate itself 180 degrees

Disaccharide bond image (beta)

…

Maltose

α-glucose and α-glucose

Lactose

β-glucose and galactose

Sucrose

α-glucose and fructose

Where is starch found and what is it made of

Plants

Mixture of amylose and amylopectin

Amylose structure and properties

alpha 1-4 glycosidic bonds

Coiled like structure

• Compact

• Doesn’t affect osmotic potential

Good for storage

Amylopectin structure and properties

alpha 1-4 glycosidic bond

alpha 1-6 glycosidic bond

• = branches

  • Allows hydrolysis at the ends by enzymes to create monosaccharides

  • = available for aerobic respiration

Glycogen structure and properties

alpha 1-4 glycosidic bond

alpha 1-6 glycosidic bond

• wont affect osmotic potential

• compact

• lost of ends to be hydrolysed to create alpha glucose = available for respiration

Similarities and differences between starch and glycogen

Made of alpha glucose

Storage mol. of carbohydrates

Similar makeup and properties

Starch = plant

Glycogen = mammal livers

Cellulose

Beta glucose - orientate itself 180 degrees

Beta 1-4 glycosidic bonds

No osmotic potential

Inert (unreactive)

Hydrogen bonds form btw. chains of cellulose = high TENSILE strength

Crosslinks btw. the microfibrils (each chain)

More in between - after thsi point starts at spec pint h, i j

Structure of a triglyceride (image)

Structure of a triglyceride (written)

3 (hydrophobic) fatty acid (tails)

1 glycerol

What bond forms between fatty acids and glycerol

Ester bonds

What is the structure of glycerol (image + words)

C₃ H₈ O₃

What is the structure of fatty acid chains (image + words)

Hydrocarbon chains

How do fatty acids and glycerol bind

Glycerol binds to the fatty acid (on carboxyl end) and water is removed (condensation reaction)

2 types of fatty acid chains

Saturated

Unsaturated

What the difference between a saturated and a non saturated fatty acid chain

Saturated, has no double bonds (every carbon is fully saturated with the hydrogen mol.)

Image of saturated and non saturated fatty acid chains

What different property does the saturated fatty acid chain make

Double carbon carbon bond = kink in chain = bend

= not as close = less dense substances such as oil

(saturated fatty acids = solid fatty substances)

Phospholipid structure (image)

Phospholipid structure (written)

two fatty acid tails

a glycerol molecule

a phosphate head

Properties of the phospholipid

Fatty acids = non polar and insoluble in water - hydrophobic

Phosphate group = polar and water soluble - hydrophilic, it orientates towards water

What is the purpose of phospholipids

Phospholipid bilayer which forms membranes

Bilayer - water on outside of cell and water on inside of cell

What structure would it form if water was everywhere around the phospholipid bilayer

Micelle structure

Micelle structure image

Triglyceride function

Good at storing energy

Respiratory substrate - release water when broken down

Insoluble - doesn’t affect water potential

Used to make hormones

Water proofing

Buoyancy

Form layers of insulation

Protective layers around organs/ nerves (myelin sheath)

Aids fat absorption - fat soluble mol. e.g vit A

Cholesterol image

Cholesterol structure

4 carbon ring structure

OH group = hydrophilic

CH section = hydrophobic

Cholesterol function

Regulates fluidity

(small size and flattened shape allow them to fit between phospholipids and bind their hydrophobic tails making the membrane more rigid)

At low temps, cholesterol increases fluidity of membranes but at high temps decreases fluidity

What’s make using cholesterol

Vitim D

Steroid hormones

Bile

SPEC POINT K, L, M

Structure of an amino acid (image)

Structure of an amino acid (written)

Central C

Hydrogen

Carboxylic group (COOH)

Amine group (NH2)

R group (changes)

What happens when two amino aids join together

A dipeptide bond forms

water is removed - condensation

Peptide bond image

What is the primary structure

The sequence of amino acids bonded by peptide bonds

Polypeptide

What is the secondary structure

Folding of the polypeptide chain

Held in place with hydrogen bonds between the r groups

(Hydrogen bonds form btw. slightly positive hydrogen and slightly negative oxygen)

Alpha helix or beta pleated sheets

What is the tertiary structure

Further folding of the polypeptide chains

Held by hydrogen bonds ( delta + Hydrogen and delta - oxygen)

Disulphide bridges (btw. 2 sulphers)

Ionic bonds (positive and negative r groups)

Hydrophobic R groups (towards center of protein)

Hydrophilic R groups (towards outside of protein)

What is the quaternary structure

More than 1 polypeptide chain