2.1.2 biological molecules

protein

made up of amino acids to form polypeptides used for growth around the body, repair, hormones, transport and for cell regeneration

Metabolism

the rate and sum of chemical reactions around the body

Carbohydrates

made up of monosaccharides to form polysaccharides in order to release energy and for structure

lipid

made up of fatty acids and glycerol in order to release energy , form membranes, insulation and protections --Non-polar macromolecules containing the elements carbon, hydrogen, and oxygen. Commonly known as fats and oils

nucleic acid

Made up of nucleotides and carries instructions for life

enzyme

A biological catalyst that lowers the activation energy of reactions in cells

Macromolecules

A very large organic molecule composed of many smaller molecules

solvent

dissolves other materials

monomer

a simple molecule with 2 or more binding sites

polymer

A long molecule consisting of many similar or identical monomers linked together.

condensation polymerisation

A process where many small molecules (monomers) join to form a large molecule (polymer) with water released

hydrosis

breaking apart a complex molecule by the addition of water

covalent bond

a bond between 2 non-metals involving a shared pair of electrons (or multiple pairs)

catalyst

speeds up a chemical reaction through decreasing the activating energy

Anabolism

formation of a larger molecule (like in condensation polymerisation)

monosaccharides

single monomer and the simplest type of carbohydrate.
formula (CH2O)n

a group of organic compounds whose molecules contain c/h/o only.
the ratio h:o 2:1
hydrated carbon

Carbohydrates

catabolism

formation of a smaller molecule (like in hydrolysis)

water -role

a solvent medium for chemical reactions to take place
used in regulating the body temperature and the formation of urea

vitamins and minerals - role

form parts of larger molecules, involved in metabolic reactions and acts as co-enzymes ( helps enzymes function properly)

properties of monosaccharides

soluble white crystalline
reducing sugars
important source of energy- good as a result of the large number of H-C bonds

hydrogen bond

found in DNA - a weak bond where the asymmetrical charges through the slightly positive and slightly negative atoms are imbalance- as more bonds are linked it becomes stronger

glucose

hexose and is used for respiration
it s the main form of sugar
polymerises to form starch

fructose

hexose
found in nectar in fruits
with glucose forms sucrose

Galactose

hexose
with glucose forms lactose

pentose
components of RNA

ribose

pentose
components form DNA

deoxyribose

molecules with the same chemical formula but different structural formula ( same molecule different forms) and also has different properties

isomere

alpha glucose

found in amylose , amylopectin, glycogen

beta glucose

found in cellulose

Disaccharides

2 monosaccharides react
sweet and soluble
lactose + maltose = reducing
sucrose = non reducing

sucrose

glucose + fructose = sucrose + water
formed in which carbohydrates are transported in the phloem of the plants

lactose

galactose + glucose
energy source for young mammals in milk

maltose

glucose + glucose ( both alpha)
formed in the breakdown of starch in germinating seeds where it provides energy for the growing embryo

Disaccharide formation

condensation reactions catalysed by enzyme
glycosidic bond is formed between the carbons 1 and 4
2 hydroxyl groups attach removing oh form 1 and h from 1 releasing water
joined by oxygen atom
reversable

What is the property of water related to its ability to resist changes in temperature?

High specific heat

What property of water is responsible for creating surface tension?

Cohesion

What property of water allows it to stick to other substances?

Adhesion

Cl- function around the body

maintains osmotic balance and forms HCl in stomach

How does water's polarity contribute to cell structure?

It holds together the lipid bilayer in cells

What makes water a universal solvent?

Its ability to dissolve a wide range of substances

covalent bond between monosaccharides

glycosidic bond

polysaccharides

hundreds of thousands of monosaccharide monomers bonded together,

large and insoluble

polysaccharides as energy stores

compact

individual molecules can easily be snipped off from hydrolysis

less soluble so don’t affect water potential of cells changing cell shapes

2 types of starch

amylose

amylopectin

amylose

long chain of alpha molecules

glycosidic bonds between carbon 1 and 4

can coil into spiral shape through hydrogen bonds

20% of starch

amylopectin

contains bonds of glycosidic binds between carbon 1 and 4 and additional between 1 and 6

forms branches

forms 80% of starch

starch

alpha glucose

compact and insoluble

in plant cells as grains

Glycogen

energy store in animals and fungi

1,4 and 1,6 glycosidic bonds

highly branches each unit 10-20 units

short chains- hydrolysed rapidly

granules in cells

cellulose

structural component

beta glucose

fibrous and indigestible

1,4 alternating glycosidic bonds rotated

parallel molecules from bundles- microfibrils - strength

lipids

contain hydrogen and a small amount of o2

non polar

3 types of lipids

triglycerides

phospholipids

steroids

trigliceriedes

1 glycerides bonded to 3 fatty acids in a condensation reaction

fatty acids can be identical or different

covalent bond = ester bond

fatty acids

carboxylic acid

can be saturated / unsaturated

unsaturated bonds push the molecules apart making it melt mor easily

functions of triglceriddes

energy sorce, energy store, insulation, buoyancy, protection

phospholipids

0.8 of lipids are phospholipids

similar to triglycerides but has 2 fatty acids and one phosphate group

phospholipid formation

phosphate group bonds to the glycerol molecules via a condensation reaction forming on an ester bons

most fatty acids n phospholipids have 16 or 18 carbons

usually one saturated fatty acid and one unsaturated fatty acid

polar

water properties for phospholipids

phosphate head = negatively charged = attracted to water= hydrophilic

fatty acids= positively charged= not attracted to water= non polar= hydrophobic

amphipathic molecule

head point towards water tails point away

phospholipid bilayer

20-80% of all cell membranes are this

2 rows of phospholipid

the tails are never exposed to water providing stability

selectively permeable membrane

micelles

arrangement of phospholipids

nanosized, spherical particles

used for drug delivery to protect hydrophobic drugs and used in skincare as it attracts and dissolves impurities

choleserol

steroid alcohol

made of carbon based rings

small and hydrophobic- sits between the hydrocarbon tails in a cell membrane

regulates fluidity

made in the liver but can be obtained from the diet

issues with excess cholesterol

in bile can clump together to form gall stones

deposits along blood vessels causing atherosclerosis

fsc- familiar hypocholesterolaemia- a genetic disorder where cells overproduce cholesterol - can cause young children to have heart attacks

amino acids

central carbon attached to a H, COOH, NH2 and an R group

over 500 different types of aa but only 20 of them are proteinogenic

essential amino acids are aa obtained from diet

amino acids in water

act as a buffer when dissolved in water

amphoteric molecule - resist changes in Ph as have both acidic and base properties

peptide bonds

amnio acids join together by peptide bonds in a condensation reaction

when enzymes are catalysed they beak these bonds in a hydrolysis reaction

peptide bons are between the c in the carboxylic acid and the N in the amine group

gobular proteins 3D structure

rolls into a ball

have metabolic roles

soluble

fibrous proteins 3d structure

regular repeated aa’s

long and thin

metabolically inactive

structural roles

insoluble

haemoglibin

globular

transport protein

soluble

4 polypeptide chains (2 alpha, 2 beta) each containing haem group

contains a prosthetic group a haem group containing an FE2= ion. and o2 molecules binds to in in the lungs

insulin

made of 2 polypeptide chains held together by a disulphide bond

soluble and transported in blood

its role is to increase the uptake of glucose by muscle and fat cell to keep blood sugar levels stable

globular

pepsin

made of 1 poly peptide chain

folds into a symmetrical tertiary structure - no quaternity structure

r groups = acidic

digests proteins

had h bonds and disulphide bridges

globular

collagen

fibrous

long - insoluble

each collagen molecule has 3 polypeptide chains

stretch and recoil

manly made of glycine

role to provide strength in artery walls tendons bones and cartilage

keratin

made of twisted coils of amino acids that form filaments

found wherever a body pat needs o be string

rich in cysteine so contains lots of disulphide bonds and hydrogen bons making it strong

it is waterproof

fibrous protein

elastin

fibrous protein

stretch and recoil

found in skin

forms a network of crosslinked molecules

primary protein structure

the order of amino acids in the polypeptide chain - it is a polymer

NOT just a chain of amino acids

secondary structure

the sequence of amino acids causes parts of a protein molecule to bend in to an alpha helix shapes or into a beta pleated sheets held in place by hydrogen bonds formed between the C=O groups of one amino acid and the H in the amine group and sometime disulphiide bonds

quaternary structure

• a protein made up of more than 1 polypeptide chain

• same bonds as tertiary (held in place by ionic, hydrogen and disulphide bonds, van der Walls forces

tertiary structure

• further folding of the secondary structure

• form a unique 3D shape

• held in place by ionic, hydrogen and disulphide bonds, van der Walls forces

• ionic and disulphide bonds (when sulphur is in both R groups) form between the R groups of different amino acids

prosthetic group

a non-peptide compound that attaches to proteins and are vital to help them function (eg fe2+ in haemoglobin)

processes around the body that ions are involved in

• catylictic activity of many enzymes

• maintain water ptential

• structural parts of tissues

• impulse transmission

• muscle contradiction

• maintaining PH

Ca+ - function in the body

• muscle contraction

• blood clotting

• signal transduction in cells

Na+ and K+ function in the body

work together to generate nerve impulses and maintain cell membrane potential essential for nerve + muscle cell function

H+ function around the body

regulate PH in cells and blood, influence enzyme activity and metabolic reactions

NH4+ function around the body

source of nitrogen in plants ( for aa and protein synthesis)

NO3- function around the body

absorbed by plants used for the synthesis of proteins and nucleic acid

HCO3- function around the body

buffering agent in blood plasma, maintains PH

PO4³- function around the body

energy storage and transfer from ATP and DNA for cellular energy and genetic material

OH- function in the body

affect PH and plays a role in biochemical reactions involving bases impacting cellular processes sensitive to PH changes.