TEM - interior SEM - surface

Animal Cell

Plant Cell

Endomembrane System

Endoplasmic Reticulum

Often referred to as ER. Makes up to 1/2 of the total

membrane in cells. Often continuous with the

nuclear membrane.

Structure of ER

Folded sheets or tubes of membranes.

Very “fluid” in structure with the membranes constantly changing size and shape.

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.

Distribution - packaging of ER products for transport.

Golgi Vesicles

Small sacs of membranes that bud off the Golgi Body.

Transportation vehicle for the modified ER products.

Lysosome Function

Breakdown and degradation of cellular materials.

Contains enzymes for fats, proteins, polysaccharides, and nucleic acids.

Over 40 types known.

Lysosomes

Important in cell death. Missing enzymes may cause

various genetic enzyme diseases.

Examples: Tay-Sachs, Pompe’s Disease

Vacuoles

Structure - single membrane, usually larger than the Golgi vesicles.

Function - depends on the organism.

Function

Water regulation. Storage of ions. Storage of hydrophilic

pigments. (e.g. red and blues in flower petals).

Function: Plant vacuole

Used to enlarge cells and create turgor pressure.

Enzymes (various types). Store toxins. Coloration.

Enzymes in a crystal

Mitochondria

Structure: 2 membranes. The inner membrane has more surface area than the outer membrane.

Matrix: inner space. Intermembrane space: area

between the membranes.

Inner Membrane

Folded into cristae. Amount of folding depends

on the level of cell activity. Contains many enzymes. ATP generated here.

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.

Inner or Thylakoid Membranes

Arranged into flattened sacs called thylakoids.

Some regions stacked into layers called grana.

Contain the green pigment chlorophyll.

Function

Photosynthesis - the use of light energy to make food.

Plastids

Group of plant organelles. Structure - single membrane. Function - store various

materials.

Examples

Amyloplasts/ Leucoplasts - store starch.

Chromoplasts - store hydrophobic plant pigments such as carotene.

Cytoskeleton

Network of rods and filaments in the cytoplasm.

Functions

Cell structure and shape. Cell movement. Cell division - helps build cell

walls and move the chromosomes apart.

Cytoskeleton

Very dynamic; changing in composition and shape frequently.

Cell is not just a "bag" of cytoplasm within a cell membrane.

Cell Wall

Nonliving jacket that surrounds some cells.

Found in: Plants Prokaryotes Fungi Some Protists

Plant Cell Walls

All plant cells have a Primary Cell Wall.

Some cells will develop a Secondary Cell Wall.

Cell Walls

May be made of other types of polysaccharides and/or silica.

Function as the cell's exoskeleton for support and protection.