Gene Expression

NCEA Level 2 Biology

Enzyme

A biological catalyst that speed up chemical reactions inside the cell.

Anabolic

build/join substrates together.

Catabolic

breaks substrates apart.

Denatured enzyme

Enzyme that lost its shape and can no longer work.

Competitive inhibition

Where inhibitor binds to active site to prevent binding of other substrates.

Non-competitive inhibition (allosteric)

Where inhibitor binds somewhere on enzyme (not active site) preventing enzyme from working (substrate can still bind). Reduces activity of enzyme.

Allosteric

Change in protein’s shape and activity when molecule binds to seperate location rather than its main active site.

Collision theory

Two or more particles must come into contact with sufficient force and at the correct orientation to have the reaction occur.

Gene

Length of DNA which codes for a protein that determines a specific characteristic.

Mutation

Permanent change in genetic material. Creates new alleles.

Mutagen

Physical agent that increase rate of mutation.

Redundancy

Where several codons code for same amino acid, lowering chance of mutation causing a different amino acid being used.

Degeneracy

Codons coding for same amino acid often differ by a single letter (nucleotide base).

Gene expression

Process in which genetic information from a gene is used to synthesise a functional protein.

Gene mutation

Occur within a gene and change base sequence of DNA.

Chromosomal mutation

Cause changes to whole chromosome

Tertiary structure

Overall 3D shape of single polypeptide chain.

Quaternary structure

Arrangement of two or more folded protein chains called subunits (tertiary structure), into single, layer functional protein complex.

Globular protein

Compact, roughly spherical protein that perform active metabolic and functional roles in body. Fragile and soluble in water.

Fibrous protein

Long, thread-like protein that provides structural strength and support to cells and tissues. Tough and strong and insoluble in water.

Metabolic pathway

Chain of chemical reactions controlled by enzymes where initial substrate converted into product (intermediate substrate) which is used as substrate for next enzyme in chain, to create final product.

Metabolite

Any small molecule produced, consumed, or left over during chemical processes of metabolism.

Missense mutation

Change in a single DNA base pair that results in code for different amino acid in a protein.

Nonsense mutation

Change in single DNA base pair that turns amino acid-coding codon into a premature stop codon, resulting in incomplete and usually nonfunctional protein.

Frameshift mutation

Genetic change caused by the insertion or deletion of nucleotides in a DNA sequence where the number of bases added or removed is not a multiple of three

Base insertion

Type of genetic mutation where an extra nucleotide base is added into a DNA sequence.

Base deletion

Type of genetic mutation where one or more nucleotide bases are lost or removed from a DNA sequence.