Biology 100 Unit 2 Exam Review Study Guide

These flashcards cover key concepts from the Biology 100 Unit 2 lecture notes, including definitions and functions related to DNA, RNA, gene expression, and regulation.

Chromatin

The complex of DNA and associated proteins in the nucleus.

DNA Replication

The process of copying the DNA prior to cell division. Occurs during S interphase

DNA polymerase

An enzyme that adds nucleotides to the growing DNA strand during replication.

Helicase

An enzyme that unwinds the DNA double helix during replication.

Ligase

An enzyme that joins together DNA fragments during replication.

Purines

The nitrogenous bases Adenine (A) and Guanine (G).

Pyrimidines

The nitrogenous bases Cytosine (C) and Thymine (T) in DNA; Uracil (U) in RNA.

Transcription

The process of synthesizing RNA from a DNA template.

Translation

The process of synthesizing proteins from mRNA at a ribosome.

Codon

A sequence of three nucleotides in mRNA that codes for a specific amino acid.

Constitutive enzymes

Enzymes that are always present and are constantly active within the cell.

Inducible enzymes

Enzymes that are produced in response to a specific stimulus or presence of a substrate.

Lac operon

A set of genes required for the metabolism of lactose in bacteria.

Allosteric regulation

A form of enzyme regulation where the function of the enzyme is affected by the binding of an effector molecule.

Methylation

The addition of a methyl group to DNA, affecting gene expression.

Degenerate genetic code

The genetic code is termed degenerate because multiple codons can encode the same amino acid.

Alternate RNA splicing

A process that allows for the generation of multiple proteins from a single gene by including or excluding specific exons.

introns

a segment of a DNA or RNA molecule which does not code for proteins and interrupts the sequence of genes

exons

a segment of a DNA or RNA molecule containing information coding for a protein or peptide sequence

tRNA

acts as an essential molecular bridge during translation, decoding mRNA sequences to synthesize proteins

rRNA

acts as a ribozyme to catalyze peptide bond formation, physically links amino acids into proteins

ribosome

found in all living cells. translate genetic information carried by mRNA, into chains of amino acids, which then fold into functional proteins

mRNA

messenger RNA, carry protein information from the DNA in a cells nucleus to the cells cytoplasm