BIOS 110 (University of Illinois at Chicago (UIC) Weeks 5-8

Biological Membranes

Fundamental structures defining cell boundaries and internal compartments, selectively permeable to maintain unique environments.

Fluid Mosaic Model

Describes biological membranes as dynamic structures with laterally moving phospholipids and proteins, with varied protein distribution.

Phospholipids

Amphipathic molecules forming bilayers in water, with hydrophilic heads and hydrophobic tails.

Integral Proteins

Proteins that span the membrane, interacting with lipid tails and heads.

Peripheral Proteins

Proteins located on the inner or outer membrane surface.

Cholesterol

A steroid that regulates membrane fluidity, acting as 'glue' in heat and 'antifreeze' in cold.

Diffusion

Movement of molecules from high to low concentration until equilibrium is reached.

Osmosis

Net movement of water across a semi-permeable membrane in response to solute concentrations.

Tonicity

Comparative terms (hypertonic, hypotonic, isotonic) indicating solute concentrations relative to another solution.

Active Transport

Movement of substances against their concentration gradient, requiring energy (ATP).

Sodium-Potassium Pump

An active transport mechanism pumping three sodium ions out and two potassium ions into the cell.

Telomerase

Enzyme that adds repetitive sequences to the ends of DNA, preventing shortening during replication.

Gene

A segment of DNA coding for a specific protein, located at a particular locus on a chromosome.

Alleles

Different versions of the same gene.

Karyotype

A profile of all chromosomes in a cell, arranged into pairs.

Missense Mutation

A mutation causing a single amino acid change in a protein.

Nonsense Mutation

A mutation that introduces a premature stop codon, often rendering the protein non-functional.

Frameshift Mutation

Mutation caused by insertions or deletions in non-multiples of three, shifting the reading frame.

mRNA

Messenger RNA that transcribes the genetic code from DNA for protein synthesis.

tRNA

Transfer RNA that carries specific amino acids to the ribosome for protein assembly.

R-selection

Reproductive strategy prioritizing high growth rates and many offspring (e.g., mice).

K-selection

Reproductive strategy prioritizing longevity and parental care (e.g., humans).

Protein Synthesis

The process of creating proteins from mRNA templates via translation.