General Biology Novare Chapter three

ATP

(adenosine triphosphate) main energy source that cells use for most of their work

Six major tenets of cell theory

1. All living things are made of cells 2. The cell is the the fundamental unit of structure and function for living things 3. Cells arise from pre-existing cells 4. Energy flow occurs within cells 5. Hereditary information is passed from cell to cell 6. All cells have the same basic chemical composition

Endoplasmic Reticulum (ER)

A cellular structure that forms a network of spaces in which proteins and other materials are produced and processed. Rough ER has embedded Ribosomes and is the site for protein production. Smooth ER has no Ribosomes and is the site for the production of lipids.

Cytoskeleton

A network of fibers that holds the cell together, helps the cell to keep its shape, and aids in movement

Nucleus

A part of the cell containing most of the DNA and RNA

cell wall

A rigid layer of nonliving material that surrounds the cells of plants and some other organisms.

Golgi apparatus

A system of membranes that modifies and packages proteins for export by the cell

Lysosome

An organelle containing digestive enzymes

Chloroplast

An organelle found in plant and algae cells that contains Chlorophyll and is the site where photosynthesis occurs

Vacuole

Cell organelle that stores materials such as water, salts, proteins, and carbohydrates. The central vacuole takes up most of the space in a plant cell.

Osmosis

Diffusion of water through a selectively permeable membrane

When is facilitated diffusion necessary in a cell?

Facilitated diffusion is necessary when cell membranes prevents a substance from diffusing on its own.

Cytosol

Fluid portion of cytoplasm used to dissolve all molecular building blocks cells make use of

Nucleolus

Found inside the nucleus and produces ribosomes

Ribosome

Makes proteins

tight junctions

Membranes of neighboring cells are pressed together, preventing leakage of extracellular fluid

passive and active transport

Passive requires no energy and active requires energy

gap junctions

Points that provide cytoplasmic channels from one cell to another with special membrane proteins. Also called communicating junctions.

Mitochondria

Powerhouse of the cell, organelle that is the site of where energy in glucose is converted to ATP

Vesicle

Small membrane-bound sac that functions in moving products into, out of, and within a cell.

Cytoplasm

The region inside the cell between the cellular membrane and the nuclear envelope in which the organelles are suspended in cytosol

extracellular matrix

The substance in which animal tissue cells are embedded, consisting of glycoproteins and collagen

Desmosomes

anchoring junctions to keep cells in place

Differences between prokaryotic cells and eukaryotic cells

prokaryotic- no nucleus, DNA is loosely contained, no separate membrane-bounded organelles, single cellular eukaryotic- Separate DNA from rest of cells in the nucleus, have membrane bounded organelles, can be multicellular