AP Biology Unit 2 Terms

Organelle

Structures within a living cell.

Prokaryotic

Usually unicellular organisms; simple cells w/ no nucleus or membrane-bound organelles.

Eukaryotic

Usually multicellular organisms; has nucleus and membrane-bound organelles.

Plasma Membrane

Protects cell and controls what goes in/out of the cell.

Cytoplasm

Area inside the cell that surrounds the other organelle

Cytosol

Semifluid substance ("jelly") inside the cell.

Centrioles

Helps cell split during cell division.

Ribosome

Creates proteins.

Nucleus

"Brain" of the cell that holds DNA in chromosomes.

Nuclear Membrane (Envelope)

Protects nucleus.

Nucleolus

Creates ribosomal RNA (rRNA)

Chromatin/Chromosome/Chromatid

Carries genetic information.

Rough Endoplasmic Reticulum

Makes proteins and transport them to the golgi via vesicles -> proteins become enzymes to help stomach or lysosomes, or become part of the membrane.

Smooth Endoplasmic Reticulum

Synthesizes (makes) lipids, detoxifies the cell, and metabolizes carbohydrates.

Golgi Apparatus

Modifies, sorts, packs, and ships proteins to where they need to go (exocytosis).

Mitochondria

Powerhouse = makes energy as ATP.

Cell Wall

Protects plant cells from water pressure (turgor).

Vacuole

Storage of waste/water/food, water control.

Chloroplast

Photosynthesis = creates sugar (chemical energy) from solar energy (light) and uses it to create energy.

Metabolism

Total chemical process to change food into energy (including breaking down and building molecules).

Selective Permeability

Ability to regulate what substances go in and out of the cell.

Cellulose

Provides structure to plant cell walls.

Plasmodesmata

Holes that connect adjacent cells to control water and molecule movement.

Concentration Gradient

Moving from high concentration to low concentration = moving to a place with LESS molecules or LESS crowded.

Diffusion

Natural flow of movement without help does not need ATP (energy).

Passive Transport

Goes with the concentration gradient (high to low) .

Simple Diffusion

Small molecules that can pass through the membrane easily.

Facilitated Diffusion

Molecules are too big or hydrophillic and need proteins' help to pass.

Channel Proteins

Like a tunnel for molecules to move through. (ex./ Aquaporin)

Carrier Proteins

"Carry" molecules through. (ex./ Sodium-Potassium pump (Na/K pump)

Active Transport

From low concentration to high concentration (to more crowded) = Against concentration gradient; requires energy to move molecules across membrane.

Endocytosis

Import of macromolecules travel through vesicles that are from the plasma membrane.

Exocytosis

Internal vesicles fuse w/ membrane to export macromolecules.