AP Biology: Unit 2

organelles

membrane-enclosed structures within a eukaryotic cell

eukaryotic cell

Cell with a nucleus and membrane bound organelles

prokaryotic cell

Cell with no nucleus nor membrane bound organelles

nucleoid region

a non-membrane-enclosed region of the cell where prokaryotic DNA is found

cytoplasm

the region in a cell between the cell membrane and nucleus; it contains the cell structures and oganelles

plasma membrane

The selective barrier that surrounds a cell; it controls what enters and leaves the cell

nucleus

chromosome-containing part of a eukaryotic cell

nuclear envelope

encloses the nucleus to separate its contents from the cytoplasm

nucleolus

located in the nucleus, makes, synthesizes, and partially assembles ribosomes

ribosomes

made of ribosomal RNA and protein, synthesize proteins

endomembrane system

organelles that are involved in the production of proteins: includes the nucleus, ribosomes, the endoplasmic reticulum, the Golgi apparatus, lysosomes, vesicles, and the cell membrane.

smooth ER

synthesize lipids, detoxifies the cell, and regulates calcium levels; portion of the endoplasmic reticulum free of ribosomes,

rough ER

organelle studded with ribosomes; produces and transports membrane and secretory proteins; partially attached to the nuclear envelope

glycoproteins

proteins with covalently-bonded carbohydrates that play a role in cell to cell interaction

vesicles

plasma membrane that moves molecules, secretes substances, digests materials,  and regulates pressure of cells

Golgi apparatus

stack of membranes that modifies, sorts, and packages proteins from the endoplasmic reticulum

lysosome

digestive system of cell: degrade material outside of cell & digest obsolete components of cell using hydrolytic enzymes

phagocytosis

the process by which a cell engulfs a solid particle

central vacuole

the largest organelle in a plant cell. It is surrounded by the tonoplast and functions to hold materials and wastes. It also functions to maintain the proper pressure within plant cells

mitochondria

chemically convert chemical (food) energy into usable ATP energy through cellular respiration

chloroplasts

an organelle in plant cells that contain chlorophyll which help absorb solar energy in order to convert carbon dioxide and water into sugars during photosynthesis

cytoskeleton

a network of fibers embracing the cytoplasm

centrioles

cylindrical organelle near the nucleus in animal cells, occurring in pairs and involved in the development of spindle fibers in cell division

flagella

a long tail-like structure that aids in cell movement

cilia

a short hair-like structures that enable movement of cells or movement of materials outside a cell, utilizes a back-and-forth motion

cell wall

extracellular structure specific to plant, bacterial, and fungal cells. protects the cell, maintains its shape, and prevents excessive water uptake

peptidoglycan

the polysaccharide in bacteria cell walls

cellulose

the polysaccharide in plant cell walls

archae

the domain of life composed of prokaryotic extremophiles

eukarya

Domain of all organisms made up of eukaryotic cells

Plasmid

A small ring of DNA that carries accessory genes separate from those of the bacterial chromosome

capsule

A sticky layer that surrounds the cell walls of some bacteria, protecting the cell surface and sometimes helping to glue the cell to surfaces.

apoptosis

programmed cell death initiated using lysosomes

isotonic solution

A solution in which the concentration of solutes is essentially equal to that of the cell which resides in the solution

hypertonic solution

A solution in which the concentration of solutes is greater than that of the cell that resides in the solution

hypotonic solution

A solution in which the concentration of solutes is less than that of the cell that resides in the solution

passive transport

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

Diffusion

Movement of molecules from an area of higher concentration to an area of lower concentration.

Osmosis

Diffusion of water through a selectively permeable membrane

facilitated diffusion

Movement of specific molecules across cell membranes through protein channels or carrier proteins

integral proteins

proteins that penetrate the hydrophobic interior of the lipid bilayer

peripheral proteins

The proteins of a membrane that are not embedded in the lipid bilayer; they are appendages loosely bound to the surface of the membrane.

active transport

Energy-requiring process that moves material across a cell membrane against a concentration difference

sodium-potassium pump

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

fluid mosaic model

model that describes the arrangement and movement of the molecules that make up a cell membrane

Plasmolysis

This happens when a cell shrinks inside a plant cell wall while the cell wall remains intact.

concentration gradient

difference in the concentration of a substance from one location to another

water potential

The physical property predicting the direction in which water will flow, governed by solute concentration and applied pressure; mostly used for plant cells

Prokaryote

A unicellular organism that lacks a nucleus and membrane bound organelles

Eukaryote

A cell that contains a nucleus and membrane bound organelles

organelle compartmentalization

the ability of eukaryotic cells to have specialized functions because they have separated compartments

Secondary active transport

Combination of active transport and passive transport

membrane potential

Difference in electric potential between interior and exterior of cell

electrochemical gradient

a gradient of electrochemical potential, usually for an ion that can move across a membrane.

Exocytosis

Molecules secreted by a vesicle that is fused with plasma membrane

Endocytosis

Molecules taken in, vesicle created by plasma membrane

Types of endocytosis

Receptor mediated & pino

Phagocytosis

bacteria (phages) taken in & broken down by lysosomes

Examples of phagocytosis

white blood cells

Bulk transport

Usually protein transported by vesicles in bulk out of cell

antiport

One substrate at a time, transport of opposite directions

Symport

Two substrates at a time, both sides of membrane

Animal Cell Vacuoles

plasma membrane that helps sequester waste products

Peroxisomes

carries out oxidative reactions using molecular oxygen, generates hydrogen peroxide

Microtubules

form part of internal skeleton of cell, serve as transportation routes for vesicles