AQA Biology: Water, Ions & Molecules Glossary

AQA Biology Key Word Glossary

• This is a compilation of key biology terms intended for memorization.

1B. Water, inorganic ions & molecules of life

• Living organisms consist of water, inorganic ions and molecules.
• Pages are labelled to find more information about the topic

Ion

• An atom that has either gained or lost an electron
• Atoms carry a resulting negative or positive charge

Ionic bonding

• This is where the involved atoms donate or receive electrons

Covalent bonding

• This is where the involved atoms share electrons

Non-polar

• A molecule with evenly spread charge across it is non-polar

Polar

• This describes the charge of a molecule where one side has a slightly positive charge and the opposite side has a slight negative charge

Intermolecular forces

• Comparatively weak bonds exist between molecules
• Hydrogen bonds between separate water molecules are examples of this

Hydrogen bond

• Temporary interaction occurs between an oxygen on one molecule and a hydrogen atom on another
• This is a type of intermolecular bond

Cohesion

• Water molecules ‘stick’ to each other via hydrogen bonding
• Water molecules attach to each other within the xylem, for example

Adhesion

• Water molecules ‘stick’ to a surface via hydrogen bonding
• Water molecules attach to the lignified cell walls in xylem, for example

Capillary action

• Adhesion and cohesion contribute to the movement of water through plants
• Adhesion of water molecules to the sides of the narrow lignified xylem vessels helps pull water up

Coolant

• A liquid that removes heat from something

Solute

• Glucose in water is an example of a substance dissolved in a solvent

Solvent

• This describes the compound other substances can dissolve in

Solution

• This describes a solute dissolved in a solvent
• Glucose in water is an example

Hydrophilic

• Polar molecules attracted to and mixable with water are hydrophilic
• Polar molecules attract to each other and are repelled by hydrophobic molecules

Hydrophobic

• Non-polar molecules repelled by and not mixable with water are hydrophobic
• These molecules attract to each other and are repelled by hydrophilic molecules

Surface tension

• Cohesive forces between water molecules lead to resistance akin to a thin film

Specific heat capacity

• This is the amount of energy needed to increase the temperature of 1kg of a substance by 1°C
• For water, this value equals 4.2kJ

Latent heat of vapourisation

• The volume of energy is required to shift a substance from liquid to vapor
• Water presents a high value for this metric due to the strength of its hydrogen bonds

Phosphate

• Is an anion needed by all living organisms, including plants and animals
• It is used in the formation of ATP and ADP, DNA and RNA

Hydrogen ions

• This is a cation needed in cellular respiration and photosynthesis
• Hydrogen ions are needed in numerous pumps and systems within organisms
• Systems that need them include pH balance and nerve impulses

Sodium

• Is a cation needed in nerve impulses
• Also helps with the cotransport of glucose and amino acids when crossing into the cells of the intestinal villi in the small intestines

Iron

• Hemoglobin contains iron as a prosthetic group
• Iron is what enables proteins to bind oxygen.
• When binding oxygen, Ferrous ion becomes Ferric ion.

Monomer

• Molecule is joinable to others of its kind
• The resulting chain makes called a polymer

Polymer

• Chain of monomers is interconnected

Polymerisation

• This anabolism is the joining of many monomers together to form a polymer

Hydrolysis

• Catabolism example requires water to break macromolecules into component monomers

Condensation

• Another anabolism type releases water to form macromolecules from component monomers

1A. Sugars, polysaccharides & lipids

• Molecule is joinable to others of its kind
• The resulting chain makes called a polymer

Carbohydrate

• Every carbon atom is connected to an hydrogen and hydroxyl group

Monosaccharide

• A carbohydrate monomer is also sugar

Disaccharide

• Carbohydrate or sugar composed of two monosaccharides
• Common disaccharides are maltose and sucrose

Polysaccharide

• A chain composed of hundreds or thousands of monosaccharides
• Common polysaccharide types are cellulose, starch and glycogen

Hexose

• This describes a monosaccharide with six carbon atoms
• Glucose, fructose and galactose are all examples

Pentose

• Any monosaccharide which has only five carbons, ribose in this kind

Ribose

• Is a pentose sugar is found in RNA and ATP

Alpha glucose

• Hexose sugar used in respiration used in the building of starch and glycogen

Beta glucose

• Hexose sugar found in cellulose fibres and more H bonds with 180 degree flip

Glycosidic bond

• This covalent bond joins sugar molecules via condensation
• Water is released as product.

Maltose

• A disaccharide with two glucose molecules
• The main sugar is discovered in germinating seed

Sucrose

• Disaccharide of one glucose molecule and one fructose molecule
• The sugar is essential in plant transport along the pholem.

Lactose

• This describes a disachharide comprised of a gaactose molecule and one glucose molecule
• Lactose is naturally seen in milk.

Reducing sugar

• In this linear form, they have a free ketone and aldehyde group
• Reacts with heated Benedict's solution and forms a brick-red precipitate.

Non-reducing sugar

• This kind doesn't have free ketone and aldehyde groups in the linear form.

Colourimetry

• This refers to measurement of a substance's absorbance at particular light wavelengths.

Calibration curve

• Determines concentration by relating light absorption of a specific substance to its content in sample.

Cellulose

• Polysaccharide constructed from beta glucose, creating linear microfibrils.
• Requires 180-degree alternation of every second beta glucose molecule

Microfibrils

• They are made up of beta glucose monomers
• Monomers come together with glycosidic links and form a strand

Starch

• Starch molecules are polysaccharide with glucose monomers, energy store for plants.

Amylose

• Polymer composed of glucose with a helical structure and 1-4 glycosidic bonds

Amylopectin

• This polymer from glucose with spiralling design and 1-4 and also 1-6 glycosidic
• Glycosidic compounds produce specific tree branching with glucose monomers.

Iodine solution

• Its for starch
• If starch exists, the solution shifts to new shade as a result.

Glycogen

• They compose bacteria and also animal electricity stores
• Is saved mostly in liver and muscle cells.

Glycoproteins

• They play tasks in immune protection and immune protection because of particular prosthetic
• This is, carbohydrate chain accessories.

Lipids

• Propane triol, also called glycerol, is a natural form seen in fats.

Glycerol

• Fatty acid chain consists of covalently bonded carbons with hydrogen on one end
• Carboxyl group on the other.

Fatty acid

• In this scenario, bond keeps the two parts linked.

Saturated fatty acid

• A fatty acid that is full of hydrogen and has single bonds only

Unsaturated fatty acid

• This fatty acid with one double carbon bond within the carbon chain.

Monounsaturated

• The fatty acid that is saturated has single double bonds.

Polyunsaturated fatty acid

• The molecular unit is the one that's got several double bonds with it.

Cis-fatty acids

• If molecules align at this bond, it is called Cis compound.

Trans-fatty acids

• H atoms are on opposites of the bond.

Triglyceride

• Three fatty acids have an accessory on a glycerol atom
• This has been put together with ester bonds during the process.

Ester bond

• There is the name of the bond, because these compounds are being bonded within these parts.
• Resulted products of condensation reaction

Cholesterol

• The molecules' functions are regulating the number of molecules and creating these.
• Molecules that make up the liquidity, while creating the force.

Amphipathic

• Molecular model with both hydrophilic or phospholipid molecules

Phospholipid

• Unusual molecules function with hydrophobic molecules.
• Phospholipid is the organic part.

Monolayer

• Unique sheet of molecule and atoms in lipids, this occurs once

Bilayer

• This is the thin or thin sheet of molecules
• Lipoprotein molecules are within the bilayer.

1A. Proteins

• Monomers that form the basis for polypeptides and so on for proteins
• There is around 20 in any total

Peptide bond

• A connection connecting two amino acids within any poly peptide
• This forms when a condensation reaction is performed.

Polypeptide

• A protein chain unit made from repeating molecules of its protein.

Denatured

• Changes in polypeptide molecules can vary from being totally unique.
• There's a chance active sites can't hold properly.

Primary structure

• Sets of arrangement of peptide in polypeptides, including number of amino acids in
• Direct series of amino acids.

Secondary structure

• This means alpha helices or beta-pleated sheets exist.
• In the three dimensional set-up of polypeptide chain.

Tertiary structure

• Creates the three-d shape of an individual complete polypeptide molecule
• May be with hydrogen, covalent or pos/neg attraction with R-groups of molecules

Quaternary structure

• Describes overall protein shape where there are a lot of them, plus prosthesis
• Prosthetics, and enzymes.

Ionic bonding

• Involved molecules get electrons or donate electrons.

Covalent bonding

• Electrons will need to be shared before molecule can bond with one another

Disulphide bonds

• Structures occur where two molecules are in sulphur, bonded near each protein part
• Is also in there
• When acids get oxidised, it generates a strong bond between molecules.

Conjugated protein

• They're prosthesis for both of them combined.
• For hemoglobin, is iron prosthesis.

Prosthetic group

• Those protein bits that is not poly peptide are added.
• And factors and assistance.

Globular

• Describes structure of proteins, like the enzyme rubisco

Fibrous

• Represents the building of a protein including length, thickness etc.
• Proteins include and keratin

Keratin

• That molecules possess in high amounts.
• It may then be challenging molecules.

Hemoglobin

• These proteins are found around
• Four chains consist of heme compounds

Insulin

• The liver produces it in order to support the storage of both those parts.

1A. Enzymes

• Biological enzyme catalyst
• Speed reactions and does not make the substrate active

Active site

• This region over the site is complementary to the substrate molecule.

Catalyst

• This element is also discovered in biological organisms.

Product

• Combination of a chemical made following enzymatic product.

Substrate

• This element allows the material, which is known as the material is modified by the enzyme.

Catabolism

• The breaking down of of macro for the monomers

Anabolism

• Mix the monomers towards macromolecule.

Metabolism

• Catalysed reactions of the entire enzyme in every part and level of organization

Metabolic pathway

• A range of reactions and where items of enzymes become reaction.

Enzyme specificity

• This describes how each enzyme can only catalyse one reaction

Enzyme-substrate complex

• This configuration where they affect each member of substrate and also distort

Activation energy

• Energy important for destroying bonds within substrate and its reaction

Lock and key hypothesis

• This describes the shape of each active area and each active region have shape specificity for

Induced-fit hypothesis

• But the active area will then change into conform
• Is being exposed so that attachment improves.

Extracellular

• External part of human body such as stomach amylase

Intracellular

• There needs to be the internal for an event to occur.

Competitive Inhibitors

• This describes where, it's like the analogue has a part.

Non-competition inhibitor

• Inhibitor that binds to an allosteric site on an enzyme
• Alters the tertiary structure so that the substrate no longer fits

Allosteric site

• Molecules which helps or prevents activity.

Negative feedback

• For this, a process's internal value creates the right setting to be at

End-product

• It's a non-competitive element

Inhibition

• An (allosteric) inhibitor regulates the first enzyme in one part

1B. DNA, RNA & DNA replication

Nucleic acids

• This is referring to the organic compounds such as DNA, RNA and ATP

DNA

• Here, the molecules preserve the genetic data which then converts into proteins

RNA

• The molecule is like DNA. It does have numerous functions, for example

Nucleotide

• Consists of a phosphate, a sugar and a nucleobase.

Nitrogenous base

• The basic structure of nucleotide to provide the ability to have many varieties