cc1 - chemical elements are joined to form biological compounds

What is an ion?

a charged particle

What is an element?

A substance containing a singular type of atom

What is a compound?

two or more elements chemically combined

What does an organic compound contain?

contains both carbon and hydrogen (can contain others too) e.g. C₆H₁₂O₆

What does inorganic compounds contain?

does not contain BOTH carbon and hydrogen e.g. H₂O

saturated

compounds in which there is a single bond present between two carbon atoms

unsaturated

compound that contains at least one double carbon to carbon bond

What is the role of calcium?

strengthen bones and teeth in animals

strengthens cell walls in plants

role of magnesium ion

a part of chlorophyll

role of iron ion

component of haemoglobin

role of phosphate ion

company of lipids and nucliec acids

dipolar

an uneven distribution of charge over the molecule

hydrogen bonds

weak forces of attraction between and reliably positive and negative molecule

metabolism

all the reactions occurring in a cell/organism

Why is water is a good solvent and what’s the significance?

because its a dipolar molecule so it can attract charged particles and seperate them

significance: allows transportation in blood and xylem, allows reactions to occur in solution of cells

Why is water being a metabolite significant?

takes part in chemical reactions in organisms

significance: photosynthesis and respiration require water

How are water molecules are cohesive and what’s the significance?

there are hydrogen bonds between water molecules

significance: surface tension creates habitat for pond skaters, in xylem water is pulled up as an unbroken column

How is H2O solid is less dense than H2O liquid and what’s the significance?

because the particles are further apart

significance: ice floats in a pond insulating the water below, provides buoyancy

Why does water has a high specific heat capacity and what’s the significance?

hydrogen bonds makes it hard to increase kinetic energy

significance: aquatic habitats experience a less extreme range of temps than terrestrial, animals and birds are 2/3 water meaning maintaining a regular body temp is easier

Why is waters specific latent heat of vaporisation being high significant?

means lots of energy required to overcome hydrogen bonds between molecules

significance: sweating has a cooling effect on skin by evaporation, transpiration has a cooling effect in plants

What’s the significance of water being transparent

significance: aquatic plants can photosynthesise in water because light passes through cells to reach chloroplasts

What are structural isomers

molecules with the same molecular formula but with different arrangements of their atoms

What are monosaccharides

single sugars, named according to the number of carbon atoms in the molecule

3 types of monosaccharides

trioses, pentoses and hexoses

What are disaccharides

sugars made from 2 monosaccharite units

what type of reaction forms disaccharites

condesation reaction (reverse is hydrolysis)

forms a glycoside bond between OH groups

maltose components and role

alpha glucose + alpha glucose

importance: intermediate in starch digestion

sucrose components and role

alpha glucose + fructose

significance: transported in phloem of plants

lactose components and role

beta glucose + galactose

energy source in milk for young mammals

alpha and beta glucose structure

storage polysaccharides

folded shape to give a compact molecule

structural polysaccharides

coiled shape or straight chained

starch

storage polysaccharide, main carb source in plants, mixture of amylose and amylopectin compounds, compact - lots of energy stored and can easily be converted to glucose for energy

glycogen

storage polysaccharide, only carb store in animals, similar structure to amylopectin, provides rapid energy when needed and regulates blood sugar levels

cellulose

structural polysaccharide, most abundant organic molecule, present in plant cell walls, long chain of beta glucose units joined by glyosidic bonds, hydrogen bonds form between OH groups, several layers of parallel fibers to strengthen structure, allows entry of water and its solutes

chitin

structural polysaccharide, found in exoskeleton of insects and fungal cell walls, structure resembles cellulose with long chains of linked monomers - cross linked with hydrogen bonds, strong, waterproof and lightweight

reducing sugars

act as a reducing agent in chemical reactions

all monosaccharides and some disaccharides

galactose, glucose, fructose, maltose, lactose

non-reducing sugars

do not act as a reducing agent in chemical reactions

includes most disaccharides and simple polysaccharides

sucrose

difference in polysaccharide to monosaccharide

polysaccharides are insoluble and not sweet to taste, monosaccharides are soluble and sweet

structural isomers of glucose

alpha glucose, beta glucose, fructose and galactose

What are amino acids, what are they composed of and what is the bond, reaction and products of making them?

Amino acids are organic compounds that serve as the building blocks of proteins. They contain an amino group, a carboxyl group, and a distinctive side chain (R group) that determines their properties. There are 20 standard amino acids that combine in various sequences to form proteins essential for various biological functions. All amino aids contain c, h, o, n and 2 amino acids contain sulphur in the r group. They bond through a condensation reaction joined by peptide bonds , producing dipeptide and water.

peptide bond

bond formed between the carbon and nitrogen when amino acids join

primary protein structure

straight chain of amino acids, only peptide bonds present, depends on type, number and sequence of amino acids

secondary protein structure

folding of the polypeptide chain, hydrogen bonds present formed between the N-H of one peptide bond and the C=0 of another, two types: alpha helix and beta pleated sheet

alpha helix - secondary protein structure

coiled structure held in place by hydrogen bonds, many weak bonds make the helix stable

beta pleated sheet - secondary protein structure

occur in polypeptide chains where sections run in parallel, many weak bonds make molecule strong

tertiary protein structure

further 3D folding of the secondary structure, forms a spherical and compact shape, gives a protein its complex and unique shape, other bonds present: disulphide bridge, ionic bonds, hydrophobic interactions

quaternary protein structure

large proteins that contain 2 or more polypeptide chains, e.g. haemoglobin has 4, same bonds as tertiary, tertiary structures interact to form quaternary

globular proteins

have a metabolic role, are compact and spherical, tertiary/quaternary structure, soluble, stability depends on temperature and pH level, very repetitive amino acid sequence, e.g. haemoglobin, antibodies, lysozomes and enzymes

fibrous proteins

have a structural role, has a rope-like structure with long fibres, secondary or occasionally quaternary, insoluble, very stable, repetitive sequences, e.g. keratin, collagen and elastin

hemoglobin

in red blood cells, respiratory pigment that binds to oxygen, primary structure pf 4 polypeptide chains (2 alpha and 2 beta), shape maintained by hydrophobic interactions, contains an iron ion (fe2+) in the haem group of each polypeptide chain

collagen

thousands of collagen molecules cross-link to form fibres , repetitive sequences of glycine, proline and hydroxyproline, hydrogen bonds form between chains giving great tensile strength and resistance to stretching

what are lipids made up of and how are they made

made up of fatty acids (contains carboxyl group COOH) and an alcohol that join via a condensation reaction, they are insoluble in water but soluble in organic solvents

the roles of lipids

can release and store twice as much energy - useful in plants and animals (especially desert), useful insulator of heat and electricity, steroids (a complex lipid) form oestrogen, testosterone and cholesterol, they can protect animals and plants with their water repellence and shock absorbing layers, create membranes in cells

what does the hydrogen tail of lipids do?

determines properties such as insolubility in water, can vary in length

unsaturated fatty acid

contains one or more double carbon bonds C=C

saturated fatty acid

contains NO double carbon bonds

what is glycerol

an alcohol with 3 hydroxyl (OH) groups

how is triglyceride formed

the three OH groups in a glycerol molecule joins with three HO groups in three fatty acids through a condensation reaction

what are phospholipids and how are they formed?

they are lipids containing a phosphate group and they are joined by a condensation reaction between a glycerol with fatty acids and phosphoric acid

structure of phospholipids

a strongly polarised, hydrophilic head with two fatty acid, non-polar hydrophobic tails. they form a double or bilayer

hydrophillic

attracted to water

hydrophobic

repels water

reducing sugars food test

benedict reagent, heat, colour change from green to orange to brick red if positive

non-reducing sugars food test

hydrochloric acid, heat, dilute sodium hydroxide, re-test with benedict reagent, colour change from green to orange to brick red if positive

protein food test

biuret solution, mix, purple if positive

lipid food test

ethanol, mix, add to water, cloudy white emulsion if positive

starch food test

iodine solution, add to sample, blue-black or red/purple colour if positive

Condensation reaction

Forms bonds, producing water

Hydrolysis reaction

Additional of water to break bonds

Where do glycosidic bonds form

Between hexoses in the production of disaccharides and monosaccharides

Where do ester bonds form?

Between glycerol and fatty acids in the production of triglycerides and phospholipids