Intro to Cells pp. 94-101

Cell Theory 3 parts of the Cell Theory: All organisms are made of one or more cells Cells are the basic unit of life Cells come only from other cells

Overview of Cell Types & Domains/Kingdoms* *Note: There has been some change in domains/kingdoms in the past 10-15 years. We will discuss it later, but this shows how prokaryotes, eukaryotes, and plant and animal cells fit together.

Prokaryotes, generally single celled organisms DNA is not membrane-bound Extremely small (1-10 micrometers) Two types: Archaea (ancient, extremophiles) Bacteria (a.k.a Monera, Eubacteria extremely diverse group)

Prokaryotic Features/Structures

Prokaryotic Structures* & their functions (1 of 2) *=not always present Capsule* = jelly-like, allows adhesion, protection from dehydration & invasion Cell wall=hard structure to protect cell Plasma membrane=separates interior & exterior of the cell, regulates movement of materials into and out of the cell Cytoplasm=Liquid-like interior-allows materials to diffuse to/from the cell’s interior structures.

Prokaryotic Structures & their functions (2 of 2) Nucleoid=Made of DNA, contains genetic information, circular, not membrane-bound Plasmids=small circular satellite DNA Ribosomes=Location of protein synthesis (60S, smaller than eukaryotes’) Flagella*=movement

Eukaryotic Cells Overview Have a membrane-bound nucleus (DNA=genetic information is inside) Have membrane-bound organelles (mini-organs) for cell functions 10x larger than prokaryotes (10-100 micrometers)

Eukaryote 1=Animal Cell Plasma membrane Lysosome Golgi apparatus Mitochondria Smooth ER Nucleus Nucleolus Rough Endoplasmic reticulum Ribosomes

Eukaryote 2=Plant Cell

Cell Size Cell size is determined by maintaining a large surface area to volume ratio Surface area = cell membrane=how materials get into and out of the cell Volume = interior of cell=proteins, DNA, cytoplasm, internal structures (must be relatively small to allow materials to move quickly.