Untitled Flashcards Set

Codon

A sequence of three nucleotide bases in mRNA that codes for a specific amino acid or signals a start or stop during protein synthesis.

Substitution mutation

A type of genetic mutation where one nucleotide base in a DNA sequence is replaced with another, potentially changing the amino acid sequence of a protein.

Insertion mutation

A mutation where one or more nucleotide bases are added into a DNA sequence, potentially altering protein synthesis.

Deletion mutation

A mutation in which one or more nucleotide bases are removed from a DNA sequence, potentially causing a frameshift.

Diffusion

The passive movement of molecules from an area of higher concentration to an area of lower concentration, driven by the concentration gradient.

Endosymbiotic Theory

A scientific theory explaining the origin of eukaryotic cells through symbiosis between ancestral prokaryotic cells, leading to the formation of mitochondria and chloroplasts.

Miller-Urey Experiment

An experiment testing if early Earth conditions could lead to the formation of organic molecules essential for life.

Sodium-potassium pump

An active transport protein that maintains ion balance by pumping 3 sodium ions out and 2 potassium ions into the cell, using ATP.

Polar molecule movement

Polar molecules move through cell membranes via osmosis, facilitated diffusion, or active transport, not simple diffusion.

Cholesterol in cell membrane

Cholesterol maintains the fluidity of the cell membrane, preventing it from being too rigid or too fluid-like.

Surface area to volume ratio

The relationship that limits cell size; as cells grow, volume increases faster than surface area, affecting efficiency in material exchange.

Functions of membrane proteins

Carrier proteins aid in transport using both active and passive mechanisms; channel proteins transport polar molecules passively.

Transcription direction

Transcription occurs in the 5’ to 3’ direction.

Flagella

Tail-like structures that enable cells to move by rotating or whipping.

Ribosomes

Organelle responsible for protein synthesis, linking amino acids into polypeptide chains.