BIO 120 Lecture Exam 2

Metabolism

The sum of all chemical reactions in a cell.

Anabolism

Builds large molecules from small ones; requires energy (uses ATP).

Catabolism

Breaks down large molecules; releases energy (makes ATP).

ATP

Adenosine triphosphate, the cell’s energy currency.

Denaturation

Loss of protein’s 3D shape → loss of function.

Osmosis

Movement of water across a semipermeable membrane.

Saprobes

Organisms that feed on dead organic matter.

Obligate aerobe

Microbe that requires oxygen to survive.

Bactericidal

Substances that kill bacteria.

Plasmolysis

Cell membrane pulls away from the cell wall due to water loss.

Codon

A 3-base sequence on mRNA coding for one amino acid.

Mutagenesis

The process of inducing mutations.

Transformation

Uptake of free DNA from the environment by a bacterium.

Transduction

DNA transfer facilitated by a bacteriophage (virus).

Conjugation

DNA (plasmid) transfer via sex pilus between bacteria.

Bacteriostatic

Substances that inhibit bacterial growth.

Genome

All the genetic material in an organism.

Nucleotide

The monomer of DNA.

Antiparallel

Describes the orientation of the two DNA strands running in opposite directions.

Dihybrid cross

A genetic cross examining two traits.

Native protein

A protein in its functional shape.

Gene

A segment of DNA that codes for a protein or trait.

Semi-conservative replication

Each new DNA molecule consists of one old and one new strand.

Hydrogen bonds

Bonds that join base pairs in DNA.

Nonsense mutation

A mutation that creates a stop codon.

Silent mutation

A mutation that changes nothing in the protein.

Facultative anaerobe

Microbe that grows better with oxygen but can grow without it.

Aseptic technique

Practices aimed at preventing contamination by pathogens.

Autoclave

Device that sterilizes using steam under pressure.