Biology - Chapter 2 OAT Revision

What does MRS GREEN stand for- movement, respiration, sensitivity, growth, reproduction, equilibrium, excretion, nutrition

What is cell theory - Cell theory states that: All living things are composed of 1 or more cells. The cell is the smallest and most basic unit of life, All cells come from pre-existing cells.

what are the two types of cells - Prokaryotic and Eukaryotic

Prokaryotic Cells - no membrane-bound organelles. Unicellular. No stable cytoskeleton. No distinct nucleus

Eukaryotic Cells - Have membrane-bound organelles. Can be either unicellular or multicellular. DNA is contained within a nucleus. Usually have stable shape and cytoskeleton.

Common Cell Features - plasma membrane, cytoplasm, DNA, ribosomes

plasma membrane -The outermost semi-permeable barrier of a cell. \n The 'gateway' into and out of the cell. composed of lipid molecules interspersed with protein channels. Material enters and exits the cell via plasma membrane. If damaged, the cell will die.

Cytoplasm - A jellylike fluid inside the cell in which the organelles are suspended

Nucleus - Contains cell's DNA.

Mitochondria - The sites of cellular respiration. Makes energy in the form of ATP. Oval-shaped organelles only found in eukaryotes.

Ribosomes - The sites of protein synthesis (translation). Made of rRNA and protein.

Endoplasmic Reticulum - The transport channels within the cell. Interconnecting system of thin membrane sheets dividing the cytoplasm into compartments and channels.

Rough Endoplasmic Reticulum (Rough ER) - Studded with ribosomes - used for quicker \n modification and sending of proteins.

Smooth Endoplasmic Reticulum (Smooth ER) - No ribosomes attached. Performs a variety of \n functions, including transport and detoxification of drugs - often found in liver & gut cells.

Golgi Apparatus - An assembly of vesicles & folded membranes which transports material out of the cell. Materials move through the ER to the Golgi Body. The Golgi Body makes modifications to the material, and then it is packaged and secreted in vesicles.

Lysosome - Recycles old, foreign or excess parts of the cell in ANIMAL CELLS. Fluid-filled sacs enclosed within a membrane.

Cytoskeleton- Three-dimensional structure which provides shape to the cell. Made of microtubules (tubular) and microfilaments (solid bundles) - flexible and can change shape

Cell Walls - Extra support and strength in plant cells. Composed of cellulose. Permeable to water, but prevents excessive uptake. Does NOT control the movement of substances in and out of the cell. Serves as barrier against infection.

Chloroplasts - Found only in plants & algae. Contain green pigments (chlorophyll). Important in photosynthesis.

Vacuoles - Large & noticeable in plant cells (animal cells have them, but they are small). \n Serves as a storage space for sugars, minerals and water.

 \n