Biological molecules

Large molecule made of monomers

Small molecule which binds to identical molecules to form polymer

Molecule split into 2 smaller molecules with the addition of water

Weak interaction, occurs when molecules contain negatively charged atom bonded to a positively charged hydrogen atom

Occurs when 2 molecules are joined together with the removal of water

Sum total of chemical reactions in the cell

Breaking down

Making new compounds

Group of molecules containing C, H and O

Bond formed between 2 monosaccharides by a hydrolysis reaction

Very large, organic molecules

Molecule consisting of glycerol, two fatty Acids and one phosphate group

Group of substances that are soluble in alcohol rather than water. Includes triglycerides, phospholipids, glycolipids and cholesterol

Monomers of all proteins, all having same basic structure

Bond formed when 2 amino acids are joined by a condensation reaction

Sequence of amino acids found in a molecule

Coiling or folding of an amino acid chain, which arises often as a result of hydrogen bond formation between different parts of the chain

Alpha helix

Beta pleated sheet

Complex 3D shape of protein molecule. Shape arises due to interactions including hydrogen and ionic bonds, disulphide bonds and hydrophobic interactions

Structure where protein consists of more than one polypeptide chain e.g haemoglobin

Long, thin structure, insoluble in water and metabolically inactive. Often having structural role within an organism

Spherical shape, soluble in water and has metabolic roles within an organism

Non-protein component that forms a permanent part of a functioning protein molecule

Nerve impulse transmission

Muscle contraction

Vital role in maintaining pH balance

Components and activators of enzymes, vitamins and hormones

Calcium

Sodium

Potassium

Hydrogen

Ammonium

Nitrate

Hydrocarbonate

Chloride

Phosphate

Hydroxide

Ca²+

Na+

K+

H+

NH4 +

NO3 -

HCO3 -

Cl-

PO4 3-

OH-

Regulation of blood pH

Rigidity of bone, teeth, cartilage and component of exoskeleton of crustaceans

Phospholipids, ATP, nucleic acids and some enzymes

Regulation of blood pH

Root growth in plants

Transport of CO2 in and out of blood

Regulation of blood pH

Production of urine in kidney and maintaining water balance

Affinity of haemoglobin to oxygen through allosteric effects of haemoglobin molecule

Producing HCl in stomach

Regulation of blood pH

Transport of CO2 in and out of blood

AAs

Proteins

Vitamins

Chlorophyll

Nucleic acids

Nitrogen cycle

AAs

Proteins

Vitamins

Chlorophyll

Nucleic acids

Nitrogen cycle

Maintenance of pH in body

Transport CO2 and O2 in blood

Regulation of blood pH

Photosynthesis and respiration

Vacuole

Maintains turgidity

Nervous transmission and muscle contraction

Healthy leaves and flowers

Control of water levels in bodily fluid

Maintenance of blood pH

Synthesis of glycogen and protein, breakdown of glucose

Active transport across cell membrane

Regulation of osmotic pressure

Control of water levels in bodily fluids

Maintenance of pH

Absorption of carb in intestines and water in kidneys

Nerve transmission and muscle contraction

Vacuole

Maintains turgidity

Rigidity of bone, teeth and cartilage

Exoskeleton of crustaceans

Clotting blood and muscle contraction

Enzymes

Muscle contraction and regulates transmission of nerve impulses

Permeability of cell membranes

Cell wall development and formation of middle lamella between cell walls

Ions humans/plants require in large amounts

Ions humans/plants need in small amounts

Display deficiency symptoms

When don't consume enough of a particular ion

Iodine

Yellow/brown

Blue/Black

Benedicts reagent and boiling

Blue

Blue -> Green -> Yellow -> Orange -> Brick red precipitate

Blue -> Green -> Yellow -> Orange -> Brick red precipitate

Blue

Add HCL, boil, add sodium hydrogen carbonate, add benedicts, boil

Regulates fluidity by binding to fatty acid tails of phospholipids

Solidifies bilayer

Increases fluidity of bilayer

Steroid alcohol

Type of lipid not made of glycerol or fatty acids

4 carbon based rings or isoprene units

Small hydrophobic molecule

Means it can sit in hydrophobic bit of bilayer

Fluidity of membrane, preventing from becoming too fluid/stiff

Liver

Ring

Stigmasterol

Has double bond between carbon 22 and carbon 23

Testosterone

Oestrogen

Vitamin D

Small and hydrophobic so can pass through hydrophobic part of bilayer

Plants

On ingestion and absorption, some can be converted to animal hormones

Cardiac poison made from steroids

Terpenes

Constructed of isoprene units

Gibberellins

Carotenoids

Phytol

Plant growth substance

Photosynthetic pigment

Component of chlorophyll

3D tertiary or quaternary structure

Regular, repetitive sequence of AAs

Insoluble in water

Form fibres, have structural function

Spherical shape

Hydrophobic R groups turn inwards and hydrophilic outwards

Water soluble

Have specific shapes

As water molecules can easily cluster round and bind to them

Collagen

Keratin

Elastin

Haemoglobin

Insulin

Pepsin

Catalase

Hydrogen

Right handed helix

Right handed helix

Lots of disulphide bridges as lots of cysteines

Quaternary structure with 4 haem groups

Enzyme that digests proteins in stomach

Digesting proteins in the stomach

Single polypeptide chain - 327 AA’s

Symmetrical tertiary structure

4 AA’s with basic R groups, 43 with acidic

Tertiary sturcture held togther by hyd bonds and disulphide bridges

4 AA’s with basic R group, 43 with acidic - very few basic groups accept H+ ions therefore there’s little effect on enzymes structure

Regulate blood glucose concentration - binds to glycoprotein receptors on outisde of muscle and fat cells to increase uptake of glycogen from blood and therefore increase rate of consumption of glucose

2 polypeptide chains - alpha and beta

Tertiary sturctue held togther by disulphide bridges

Hydrophilic R groups on outside

Weak interactions between subunits

Hydrophilic R groups are on outside

Globular protein that contains a non-protein component called a prosthetic group

Simple protein

Quaternary structure has 4 polypeptide chains - 2 alpha, 2 beta

Iron prosthetic group

Carry O2 from lungs to tissue - In lungs, O2 molecule binds to iron groups forming oxyhaemoglobin, turning from purple red to bright red. O2 released when reaches tissues

Quaternary structure made from tropoelastin

Coiling and cross-linking making it strong and flexible

Skin to stretch around bones and muscles

Lungs to deflate and inflate

Bladder to expand and hold urine

Blood vessels and stretch and recoil as blood pumped to maintain pressure

Mechanical strength and impermeable barrier to infection

Waterproof for preventing entry of water-bourne pollutants

Finger nails, hair, claws, scales

Right handed alpha helix

Rich in cycteine so lots of disulphide bridges and hyd bonds - very strong

3 polypeptide chains - hyd bonds forming triple helix

Left handed helix

1/3 AA’s in collagen is glycine

Rope like sturcture - very strong

Cross-links between molecules - covalent bonds

Mechanical strength

Artery walls - prevents bursting from high pressure from heart

Tendons - connect muscles to bones allowing them to pull

Make up cartilage and conective tissue

Bones - made form collagen and reinforced with calcium phosphate to make them hard

Energy source

Energy store

Insulation

Buoyancy

Protection

Cell surface membrane

Ethanol emulsion test

1. Mix sample with ethanol to dissolve lipid

2. Pour into water

3. If lipid present, will form at top as cloudy white emulsion

Can be broken down in respiration to release energy and generate ATP. Hydrolyse ester bonds, then glycerol and fatty acids broken down completely to CO2 and H2O.

Have fat around delicate organs to cat as shock absorber

Peptidoglycan cell wall is covered in lipid-rich outer coat

Fats less dense than water so used by aquatic animals to float

Hibernating animals store extra fat

Adipose tissue is storage location for whales, acting as heat insulator

Lipid in nerve cells act as electrical insulator

Insoluble so can be stored without affecting water potential of cell

In adipose cells under skin

Twice as much energy as 1g of glucose

Because lipids have higher proportion of hydrogen atoms than carbohydrates and almost no oxygen atoms

Triglycerides

Phospholipids

Cholesterol

Carboxyl group (head)

Methyl group (tail)

Large amounts of carbon and hydrogen with small amounts of oxygen

No they're insoluble

Not polar so don't attract water molecules

Alcohol

No they're macromolecules

1 glycerol molecule

3 fatty acids

Most in body but some must be ingested 'complete'

Essential fatty acids

3

As it's an alcohol

3

Carboxyl group one end of hydrocarbon chain

Carboxyl group ionises into H+ and a COO- group - structure acid as can produce free H+ ions

Straight and solid

Kinked and liquid

C2H2nO2

At least one double bond between two of the C atoms

Single C=C

Having more than 1 C=C

Kink pushes molecule apart slightly

Saturated

Lower melting point

Condensation reaction between COOH group of fatty acid and OH group of glycerol

3

1 Glycerol molecule

3 Fatty acids

Condensation reaction

Ester bond (covalent) bond formed

H2O formed

1 triglyceride molcule

3 H2O

C H O

S O N C H

P O N C H

Monosaccharides

Amino acids

Nucleotides

Polysaccharides

Polypeptides and proteins

DNA and RNA

Dimer

Polymers

Yes

Sharing electrons with other atoms so outermost shell can be filled to become stable

Two - OH groups react together

Forming covalent bond

Breaking of covalent bond

H2O

H2O

Bond between slightly positively charged atom and negatively charged atom

No it's a weak interaction

Covalent

As there a many of the bonds

Two hydrogen atoms and one oxygen atom covalently bonded

Oxygen has greater number of positive electrons in nucleus so exerts a stronger attraction for shared electrons. The oxygen becomes negative and the hydrogen positive

C6H1206

C6H12O6

C5H10O5

C5H10O4

Energy source

Component starch and glycogen (act as energy stores)

Energy source

Component of cellulose - provides support in cell walls

Component RNA, ATP and NAD

Component of DNA

Maltose

Sucrose

Lactose

When 2 monosaccharides joined togther

maltose

sucrose

lactose

cellulose

Condensation reaction

Maltose formed

a 1-4 glycosidic bond between molecules

H2O molecule formed

-ose

Sweet

Water soluble

Insoluble in non-polar solvents

(CH2O)n

Straight chains or rings or cyclic forms

Triose

Tetrose

Pentose and hexose

Cx(H2O)y

CO2 + Water

Starch in starch grains and chloroplasts

Glycogen in muscle and liver cells

No

Compact - don’t take up much space

Glucose molecules held in chains and can easily be snipped off by hydrolysis when needed for respiration

Amylopectin and glycogen

Amylose

Hydrolysing 1-4 glycosidic linkages

Hydrolysing 1-6 glycosidic linkages

Water pot would reduce & excess water would diffuse in to cells, disrupting workings

Long chain a-glucose molecules

Forms a1-4 glycosidic bonds

Spiral shape - hyd bonds

a1-4 glycosidic bonds and a1-6 glycosidic bonds to form branches

Branched spiral shape

a1-4 and a1-6 glycosidic bonds

Branched straight chain

Each molecule has large number of glucose molecules - high energy content

a1-4 link easily hydrolyed by enzymes - release glucose rapidly

amylose: compact helical shape, amylopectin: compact branching structure - compact so easy to store

Plant cell walls

Tough

Insoluble

Fibrous

Condensation reaction

Long chains b-glucose molecules

Glycosidic bond fomed

H2O formed

Secind molecule rotated by 180

Rotating molecules by 180

b1-4 glycosidic bonds

60-70

Bunching of microfibrils

Criss-cross cell wall for extra strength

No as most OH groups are inaccessible to water

Yes as b1-4 links aren’t easily hydrolysed

Spaces between macrofibrils for water and mineral ions to pass in and out of cell

High tensile strength due to strength of glycosidic bonds and hydrogen bonds between chains - stops cells bursting when turgid

Difficult to digest as glycosidic bonds between glucose molecules hard to break - defence against insects

Peptidoglycan - made from long polysaccharide chains that lie parallel, cross linked by short peptide chains

Chitin

1 glycerol

2 fatty acids

1 phosphate group

Ester bonds

Yes as polar

Amphipathic

amphipathic

Unsaturated fatty acid so contains C=Cs

Only possible for small and non-polar molecules to pass through hydrophobic, non-polar tails of bilayer

Structural

Membrane carriers

Enzymes

Hormones

Antibodies

Receptors

Transport

AA’s you must ingest (can’t manufacture in body)

Yes as long as have access to fixed nitrogen

Amino group

Carboxyl group

R group

Those with an acidic R group

Peptide bonds

Dipeptide molecule formed

Condensation reaction

Peptide bond

1 H2O formed

Protease enzyme

Dissolved in water - amino and carboxyl groups can ionise

COOH -> <- COO- + H+ (acts as acid producing H+ions)

NH2 + H+ -><- NH3- (acts as base accepting H+ ions)

Specific sequence of AA’s joined togther by peptide bonds to form polypeptide chain

Shape and therefore function

Folding/coiling of primary structure into:

Alpha helix

Beta pleated sheet

Hyd bonds between -NH of one AA and -Co group of another 4 places down

Hyd bonds between -NH of one AA and -CO of another further down

Although hyd bonds weak, many formed making strong

Heating - heat increases K.E of molecules causing to vibrate and break bonds holding tertiary sturcture. Structure unfolds chainging shape of protein

Folding of secondary structure into compact 3D shape (fibrous or globular)

Hyd - between R groups

Disulphide - between residues of cystine which contain sulfur

Ionic bonds - between charged groups

Structure consisting of more than one polypeptide chain

Peptide bonds

They’re covalent bonds

Hydrogen

Hydrogen

Between carboxyl and amino groups that are part of R group

Between R groups of 2 cysteins as contain S

Covalent

High temps or change in pH

Altered pH

Reducing agents

Liquid

Density

Good solvent

Cohesion and surface tension

High specific heat capacity

High latent heat of vapourisation

Reactant

Water molecules hyd bonded together

Water molecules hyd bonded to surfaces

Important reactant for digestion and synthesis of large molecules

Molecules/ions can move about and react togther in water

Molecules/ions can be transported whilst dissolved in water

Is polar so +ve and -ve part attracted to +ve and -ve parts solute - cluster around charged parts of solute moleules/ions and help seperate them to dissolve them

Weak hyd bonds

provides ideal habitat - if less dnese, aquatic animals would find difficult to float

Gets more dense until 4C - as goes from 4C-0C, molecules align themselves in structure which is less dense than liquid water

Aquatic animals have stable enviro through winter

Bodies of water insulated against extreme cold - layer of ice reduces heat loss

Provides habitat in rivers, lakes, sea

Major component of tissue in organisms

Reaction medium

Effective transport medium e.g blood

Columns of water in plant vascular tissue pulled up xylem tissue togther from roots

Insects e.g pond skater can walk on water

Means doesn’t heat/cool easily - need stable temp for enzyme contolled reactions and for living

Energy required to raise temp of 1kg of water by 1C

Molecules can break away from each other forming a gas - can help cool living things and keep stable temps e.g mammals sweat to cool and it evaportaes