THE CELL

Cell Theory

All organisms are composed of cells

All cells come from pre-existing cells

Cells are the basic unit of structure and function of all organisms

Organelles

Special structures in a cell that carry on the life functions of a cell

The “organs” of an individual cell

There are two types of cells found in all organisms

Prokaryotic Cells-– small considered primitive

Eukaryotic Cell –– up to 10x larger,more advanced

Prokaryotic vs Eukaryotic

Found only in Kingdoms Archaebacteria, and Eubacteria

No “true” nucleus

No “true” organelles

Found in Kingdoms Protista, Fungi, Plantae, and Animalia

Posses a “true” nucleus with genetic material (DNA)

Posses true organelles

Basic Cell Anatomy

3 Main Parts of a Cell– Nucleus– Plasma Membrane

surrounds the cell

– Cytoplasm where the organelles are located

Nucleus (the Boss of the cell)

Functions of the Nucleus– Controls all cell activities– Stores hereditary info. in the form of DNA

DNA has the coded information for making the proteins and other substances important to the life of the cell

Parts of the Nucleus (pg.181)

Nuclear envelope- surrounds and encloses the nucleus (absent in prokaryotic cells)

Nuclear pores- holes in the nuclear envelope that allows “stuff” into or out of the nucleus

Chromatin- made up of DNA and protein

Nucleolus- Dark dense structure in the middle of the nucleus that produces ribosomes

THE NUCLEUS

Chromatin

Nuclear Envelope

Nucleolus

Nuclear pore

The Plasma Membrane

Thin barrier around a cell that controls what enters and leaves a cell.Cytoskeleton- found in the plasma membrane it is a system of tubules and fibers that support the cell and maintain its shapeParts of the cytoskeleton also functions in locomotion of the cell (Ex. cilia and flagella)

Cilia and Flagella

Cilia- short hair-like projections that row the cell through the water

Flagella- long whip-like projections that propel a cell through the water.

CILIA

Cytoplasm

The liquid part of the cell located between the nucleus and the plasma membrane

Contains the organelles (where most activities of the cell occur)

Organelles in the cytoplasm pp.180-187

Ribosomes

Endoplasmic reticulum

Golgi

Lysosomes

Vacuoles

Mitochondria and Chloroplasts

Ribosomes

Small bead-like organelles found floating in the cytoplasm, called free ribosomes, or attached to the endoplasmic reticulum, called attached ribosomes.

Function of ribosome

Where proteins are made– Receives the information from the nucleus– Free ribosomes proteins made there are for

use in the cell.– Bound ribosomes proteins made there are for

export outside the cell.– Cells that are active in protein production are

often packed with ribosomes.

Endoplasmic reticulum (ER)

Folded membrane where parts of the cell membrane are made and proteins are constructed

Two types of Endoplasmic Reticulum

1. Rough ER- Called rough ER because it has ribosomes attached to its outer surface where proteins for export and membranes are made.

2. Smooth ER- makes lipids and detoxifies drugs and poisons

The Golgi

Stacks of flattened sacs found in the cytoplasm

Function- modifies, sorts, packages and routes the products of the ER

Often called the “warehouse” of the cell

The man The apparatus

Lysosomes

Small liquid filled compartments in the cell– Function- contain digestive enzymes to

breakdown material needed by the cell– Also- digest old worn out organelles (recycling

of “old” cell parts)

Golgi and Lysosomes

Vacuoles

Provides storage for water, salts, and food for the cell.

Food Vacuole

Mitochondria

Generate energy for the cell

Often called the “powerhouse” of the cell

Chloroplasts

Found only in plant cells. They capture light energy and convert it into chemical energy in the form of glucose. This process is called photosynthesis.

Cell wall

Found only in plant cells and Fungi

Helps support and protect the cell.

THE CELL