Cell Theory
All living matter is composed of one or more cells.
The cell is the structural and functional unit of life.
Types of Cells
Prokaryotic - lack a nucleus and other membrane bound structures.
Eukaryotic - have a nucleus and other membrane bound structures.
Organelle
Term means "small organ” Formed body in a cell with a specialized function.
Important in organizational structure of cells.
Organelles - function
Way to form compartments in cells to separate chemical reactions.
Keeps various enzymes separated in space.
Plant vs Animal Cell
Plants Have a large central vacuole to
hold water Contain chloroplasts Have cell wall made of
cellulose
Nuclear Membrane
Double membrane
Nuclear Pores Allow things in and out of
nucleus Ex. mRNA during
transcription
Chromatin
Chrom: colored - tin: threads DNA and Protein in a “loose”
format. Will form the cell’s chromosomes.
Ribosomes
Structure: 2 subunits made of protein and rRNA. No membrane.
Function: protein synthesis. Site of translation
Endoplasmic Reticulum
Folded sheets or tubes of membranes.
Membrane is continuous with the nuclear membrane
Types of ER
Smooth ER: no ribosomes. Used for lipid synthesis,
carbohydrate storage, detoxification of poisons.
Rough ER: with ribosomes. Makes secretory proteins.
Function of Golgi Bodies
Processing - modification of ER products (lipids, carbs).
Distribution - packaging of ER products for transport.
Vesicles
Small sacs of membranes that bud off the Golgi Body.
Transportation vehicle for the modified ER products.
Function
Breakdown and degradation of cellular materials.
Contains enzymes for fats, proteins, polysaccharides, and nucleic acids.
Over 40 types known.
Vacuoles
Structure - single membrane, usually larger than the Golgi vesicles.
Function – store water, and sometimes other molecules
Mitochondria
Structure: 2 membranes. The inner membrane has more surface area than the outer membrane.
Matrix: inner space. Intermembrane space: area between
the membranes.
Function
Cell Respiration - the release of energy from food.
Major location of ATP generation.
“Powerhouse” of the cell.
Chloroplasts
Structure - two outer membranes.
Complex internal membrane. Fluid-like stroma is around
the internal membranes.
Functions
Cell structure and shape. Cell movement. Cell division - helps build cell
walls and move the chromosomes apart.
Centrioles
Usually one pair per cell, located close to the nucleus.
Found in animal cells. Help in cell division.
Cell Wall
Nonliving jacket that surrounds some cells.
Found in: Plants Prokaryotes Fungi Some Protists