Unit 2 AP Biology terms

Nucleus

The membrane-bound organelle that contains the cell's genetic material and controls cellular activities.

Rough endoplasmic reticulum

A type of endoplasmic reticulum studded with ribosomes, involved in protein synthesis and processing.

Smooth endoplasmic reticulum

A type of endoplasmic reticulum that lacks ribosomes and is involved in lipid synthesis and detoxification.

Golgi Apparatus

Modifies, sorts, and packages proteins and lipids for secretion or delivery to other organelles.

Lysosome

Contains digestive enzymes to break down waste materials and cellular debris, playing a key role in cellular recycling.

Central Vacuole

Found in plant cells, it stores nutrients and waste products, and helps maintain turgor pressure.

Cell Membrane

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

Fluid Mosaic Model

Describes the cell membrane as a dynamic structure with various proteins floating in or on the fluid lipid bilayer, allowing for flexibility and movement.

Phospholipid

A molecule with a hydrophilic (water-attracting) head and two hydrophobic (water-repelling) tails, forming the basic structure of cell membranes.

Integral and Peripheral Proteins

span the membrane and are involved in transport, while are attached to the exterior or interior surfaces and play roles in signaling and maintaining the cell's shape.

Diffusion Efficiency

the proportionality between flux and concentration gradient.

Facilitated Diffusion

A type of passive transport that uses channel or carrier proteins to help move substances across the membrane without energy input.

Active Transport

The movement of molecules against their concentration gradient, requiring energy (ATP), such as the sodium-potassium pump.

Endocytosis and Exocytosis

Processes for transporting large molecules into _______ or out of _________ the cell via vesicles.

Water Potential

A measure of the potential energy in water, influencing the movement of water in and out of cells, calculated as the sum of solute potential and pressure potential.

Solute Potential

The effect of solute concentration on water potential; the more solute present, the lower the solute potential (more negative).

Pressure Potential

The physical pressure on a solution; in plant cells, turgor pressure contributes positively to water potential.

Turgor Pressure

The pressure exerted by the fluid in the central vacuole against the cell wall, crucial for maintaining plant structure and rigidity.

Hypertonic Solution

A solution with a higher solute concentration compared to the cell, leading to water loss and cell shrinkage.

Hypotonic Solution

A solution with a lower solute concentration compared to the cell, causing water to enter the cell and potentially leading to lysis.

Isotonic Solution

A solution with equal solute concentration to the cell, resulting in no net movement of water and maintaining cell size.

Prokaryotes

Simple, unicellular organisms without a nucleus or membrane-bound organelles (e.g., bacteria and archaea).

Eukaryotes

More complex cells with a defined nucleus and organelles, including plants, animals, fungi, and protists.

Endosymbiosis

A theory that explains the origin of eukaryotic cells from prokaryotic organisms, suggesting that mitochondria and chloroplasts originated as free-living bacteria that were engulfed by ancestral eukaryotic cells.

The surface to volume ratio

As a cell grows, its volume increases much faster than its surface area does.

Vesicle

A membrane bound sac that contains materials involved in transport of the cell.

Ribosome

Makes proteins

Cell Wall

A rigid structure that surrounds the cell membrane and provides support to the cell

Flagella

A long, whip-like filament that helps in cell mobility.

Cilia

The hairlike projections on the outside of cells that move in a wavelike manner

Cholesterol

Maintain proper fluidity of membrane in various temps. In the cold, it maintains space between phospholipids to keep them mobile. In hot, fills space between phospholipids and interacts with them to prevent too much mobility.

Transpiriation

the process by which plants release water vapor through their leaves

Channel Protein

a protein that allows the transport of specific substances across a cell membrane

Carrier Protein

Transport protein that changes shape when a particle binds with it

Sodium-potassium pump

a carrier protein that uses ATP to actively transport sodium ions out of a cell and potassium ions into the cell

Membrane potential

difference in electric potential between the interior and the exterior of a biological cell.

Passive transport

Requires NO energy, Movement of molecules from high to low concentration, Moves with the concentration gradient

Electrochemical gradient

Determines the direction that ions will flow through an open ion channel

Mitochodria

cell oraganells surrounded by two membranes that break down food molecules to make ATP

Chloroplast

organelle found in cells of plants and some other organisms that captures the energy from sunlight and converts it into chemical energy

vacuole

A sac inside a cell that acts as a storage area