NAT5 biology unit 1

Active Site

The position on the surface of an enzyme molecule to which a specific substrate molecule can bind.

Active transport

The movement of molecules against their concentration gradient (using energy).

Adenine

The base that pairs with Thymine in a DNA molecule

Aerobic Respiration

The release of energy from food using oxygen.

Amino Acids

Units from which proteins are composed. There are about 20 different types.

Anaemia

Medical condition that develops as a result of iron deficiency

Antibodies

A group of protiens involved in body defences (i.e. the immune system).

ATP (adenosine triphosphate)

The energy currency of the cell. Energy in this form can be used by cells for muscle contraction, cell division, protein synthesis and transmission of nerve impulses

Bases

Chemical components of DNA. There are four different types (A,T,C & G)

Blight resistance

A characteristic of some potato plants that makes them resistant to blight. The genetics behind the characteristic are of interest to plant geneticists

Carbon Dioxide

A gaseous waste product of the breakdown of glucose during respiration.

Catalysts

Chemicals that speed up reactions without being used up or changed in the process.

Cell membrane

Is made of proteins and phospholipids. It controls the entry and exit of substances into and out of the cell (it is selectively permeable).

Cell membrane

It is made of proteins and phospholipids. It controls the entry and exit of substances in and out of the cell.

Cell Wall

The outer layer of plant, fungal and bacterial cells. It helps to support the cell.

Cellulose

A structural carbohydrate from which plant cell walls are composed.

Chlorophyll

The green pigment found in chloroplasts that absorbs light energy for photosynthesis.

Chloroplasts

Membrane-bound organelles that contain chlorophyll and are the site of photosynthesis in plant cells.

Chromosomes

Threadlike structures found within the nucleus of plant and animal cells. Packages of DNA and protein.

Complementary

Word used to describe things that go together (like a hand in a glove). With reference to DNA it describes the fact that A pairs with T and C pairs with G.

Complementary

Word used to describe things that go together (like a lock and key). With reference to enzymes it describes the fact that the active site is shaped to fit a particular substrate.

Concentration gradient

The difference in concentration between two places.

Cytoplasm

A watery, jelly-like material within cells that is the site of chemical reactions. Contains enzymes.

Cytoplasm

The location of the first stage of respiration and also of the FERMENTATION pathway

Cytosine

The base that pairs with Guanine in a DNA molecule

Degradation Reactions

Reactions in which large, complex substrates are broken down into smaller, simpler molecules.

Denatured

Describes an enzyme that has changed shape as a result of extremes of temperature or pH. An enzyme in this state will no longer work.

Diffusion

The passive movement of molecules from an area of high concentration to and area of lower concentration down a concentration gradient.

DNA (deoxyribonucleic acid)

The substance in chromosomes that carries the genetic code of an organism.

DNA (deoxyribonucleic acid)

The substance in chromosomes that carries the genetic code of an organism.

Donor

Organism from which genetic information is obtained for transfer to another species

Double Helix

The shape DNA. Describes its two adjacent polynucleotide strands wound into a spiral shape.

Enzyme-Substrate Complex

Formed when an enzyme and its substrate are joined at the active site.

Enzymes

A group of proteins that control the reactions of respiration

Enzymes

Biological catalysts which speed up vital chemical reactions in living things.

Enzymes

Proteins that act as catalysts, speeding up reactions in all living cells.

Ethanol

An alcohol produced (along with Carbon Dioxide) during fermentation in plant and yeast cells

Fatigue

The result of a build up of lactate within muscle cells during fermentation

Fermentation

Process by which cells release energy in the absence of oxygen

Gene

A section of DNA on a chromosome that codes for the synthesis of a protein and thus controlls a trait.

Genetic Code

The order of bases on a DNA molecule. Each group of 3 bases codes for an amino acid. The order of the bases determines the order of the amino acids linked together to make a protein.

Genetic engineering

The artificial transfer of genetic information from one cell or organism to another

Genetics

The study of genetic material and its transmission from generation to generation.

Glucose

A simple sugar that is a store of chemical energy which can be released through the process of respiration.

GMO (genetically modified organism)

General term for an organism that is produced by applying genetic engineering techniques

Golden Rice

GM rice variety modified so that it produces Beta-carotene (which is important in the production of Vitamin A) and iron

Guanine

The base that pairs with Cytosine in a DNA molecule

Hormones

Proteins that act as chemical messengers between cells. They are produced by endocrine glands and travel in body fluids such as blood.

Human Growth Hormone (HGH)

A hormone that controls growth during childhood and adolescence - can now be produced by genetic engineering and used to treat patients who do not produce enough of their own

Hydrogen Bonds

Weak bonds that exist between complementary bases in a DNA molecule and hold the polynucleotide strands together.

Insulin

A hormone that is important for the regulation of blood sugar levels - now produced by genetically engineered bacteria and used in the treatment of diabetes

Iron

An essential mineral needed by the body for the production of red blood cells

Lactate

A 3-carbon compound produced from pyruvate during fermentation in animal cells

Lipids

Fats and oils composed of fatty acids and glycerol.

Mitochondria

The cell's power stations. They are the site of aerobic respiration in plant, animal and fungal cells. Cells with a high energy demand have more of these eg. muscle cell and sperm

Mitochondria

The location of the second, aerobic stage of respiration

mRNA (messenger ribonucleic acid)

Substance that carries a complementary copy (transcript) of the genetic code from the DNA to the ribosomes.

Multicellular

An organism that is composed of many cells.

Nucleotides

The units from which DNA molecules are formed. Each one consists of a deoxyribose sugar, a phosphate and a base.

Nucleus

Contains chromosomes which carry genetic information and so controlls all of the cells activities.

Nucleus

It contains chromosomes which carry the genetic information and so controls all of the cells activities.

Optimum

Describes the conditions (of temperature and pH) at which an enzyme works best.

Organelles

Membrane-bound compartments with a specific function found within plant, animal and fungal cells.

Osmosis

The diffusion of water through a selectively permeable membrane.

Oxygen

A gas that is necessary for the efficient release of the energy stored within a glucose molecule during aerobic respiration.

Oxygen debt

A cumulative deficit of oxygen resulting from intense exercise

Passive

Not requiring energy.

Permeable

Allowing liquids or gases to pass or diffuse through.

Photosynthesis

The process by which green plants make their own food by capturing sunlight energy.

Plasmid

Small, circular length of DNA found within bacterial cells - often used as vectors in genetic engineering

Plasmids

Circular loops of genetic material found within bacterial cells.

Plasmolysed

This term describes plant cells in which the vacuole has shrunk and the membrane has pulled away from the wall due to water loss.

Polynucleotide

A long chain of nucleotides linked by strong chemical bonds.

Potato Blight

A fungal disease of the potato plant that was responsible for the potato famines in Scotland and Ireland in 1845/46

Products

The substances that are made by a chemical reaction.

Proteins

Molecules composed of long chains of amino acids (polypeptides). The order of the amino acids determines the shape of the molecules and the shape determines their function.

Proteins

Molecules composed of long chains of amino acids (polypeptides). The order of the amino acids determines the shape of the molecules and this in turn determines their function.

Pyruvate

Two molecules of this 3-carbon compound are produced by splitting a glucose molecule in two during the first stage of respiration

Reaction Rate

A measure of how quickly the substrate is being converted into products. We can measure how quickly the concentration of the substrate decreases OR how quickly the concentration of the products increases.

Receptors

Proteins found within cell membranes that "recognise" specific substances.

Recipient

A cell or organism that receives genetic information from a donor cell or organism

Respiration

A series of enzyme-controlled reactions that releases energy in all living cells.

Ribosomes

Small almost spherical structures found in the cytoplasm of all cells. They are the site of protein synthesis.

Ribosomes

Small almost spherical structures found in the cytoplasm of all cells. They are the site of protein synthesis.

Selectively permeable

This term refers to a membrane that controls the movement of certain molecules depending on their size.

Specific

Describes the fact that each enzyme acts on one substrate only.

Structural Proteins

Proteins that give strength and support to cellular structures. They are found in membranes, bones, hair, nails etc.

Substrate

The substance on which an enzyme works.

Sugar-Phosphate backbone

Describes the strong bonds that link nucleotides together to form a DNA strand (the uprights of the ladder).

Synthesis Reactions

Reactions in which simple substrates are combined to make larger, more complex molecules.

Thymine

The base that pairs with Adenine in a DNA molecule

Triplet code

Describes the fact that the code carried on a molecule of mRNA is translated at a ribosome 3 letters at a time.

Turgid

This term describes a swolen plant cell with a full vacuole resulting from water intake due to osmosis.

Ultrastructure

The fine structural detail of a cell as revealed by powerful magnification.

Unicellular

An organism such as a bacteria that is composed of only one cell.

Vacuole

A membrane-bound organelle that stores a solution of water, salts and sugars (cell sap) in plant and fungal cells.

Vector

Transports genetic material from one organism to another

Virus

Microorganism often used as a vector in genetic engineering

Vitamin A

In 2012 the World Health Organization reported that about 250 million preschool children suffer from deficiency in this vitamin - a condition which can lead to blindness and death

Water

Waste product of respiration that forms when oxygen combines with hydrogen.