ap bio unit 2 - cell structure and function

Prokaryote

Prokaryote

A type of cell without membrane-bound organelles, with free-floating genetic information and circular DNA.

Eukaryote

A type of cell that contains membrane-bound organelles and has a more organized structure.

Endosymbiotic theory

The theory explaining how organelles like mitochondria and chloroplasts arose from large prokaryotes engulfing smaller prokaryotes.

Nucleus

The organelle that contains genetic information, including DNA and RNA, and has a core called the nucleolus.

Endoplasmic Reticulum (E.R.)

An organelle used to synthesize macromolecules; includes rough E.R. (with ribosomes) and smooth E.R. (without ribosomes).

Golgi apparatus

An organelle that modifies and packages proteins, made from the E.R.

Lysosome

An organelle used for digestion and breaking down materials inside the cell, containing hydrolytic enzymes.

Vacuole

Membrane-bound sacs with various functions, prominently large in plant cells.

Mitochondria

The organelle where ATP is produced in eukaryotes, featuring a double membrane and evidence for endosymbiotic theory.

Chloroplast

The organelle where photosynthesis occurs, containing chlorophyll and two membranes.

Cell wall

A structure found outside the cell membrane in plant cells, providing support and structure, made of cellulose.

Ribosomes

The site of protein translation, present in all cells, indicating a common ancestor.

Cell membrane

A phospholipid bilayer that regulates the movement of substances in and out of the cell.

Passive transport

Movement of substances across a membrane without energy, from high to low concentration.

Active transport

Movement of substances against the concentration gradient using energy (ATP) and a protein.

Tonicity

The measure of solute concentration in a solution, affecting water movement.

Hypertonic

A solution where water moves into it, causing plant cells to plasmolyze and animal cells to shrivel.

Hypotonic

A solution where water moves out, causing plant cells to become turgid and animal cells to potentially burst.

Isotonic

A solution where water moves in and out at equal rates, resulting in no net change.

Water potential (Ψ)

A measure of the potential energy of water in a system, calculated as Ψ = Ψs + Ψp.

Solute potential (Ψs)

The measure of how much solute is dissolved in water, becoming more negative with increased solute concentration.

Solute potential formula

Ψs = -iCRT, where i is the number of ions, C is molar concentration, R is the gas constant, and T is temperature in Kelvin.