Download Cell Membrane

Lab:2
Biology 1 stage
The cell:
A cell is the smallest unit that is capable of performing life functions.
Discovery of Cells
• Robert Hooke (mid-1600s)
– Observed sliver of cork
– Saw “row of empty boxes”
– Coined the term cell
Cell Theory
1. All living things are made up of cells.
2. Cells are the smallest working units of all living things.
3. All cells come from preexisting cells through cell division
Principles of Cell Theory:
1. All living things are made of cells
2. Smallest living unit of structure and function of all organisms is the
cell
3. All cells arise from preexisting cells(this principle discarded the
idea of spontaneous generation)
Characteristics of All Cells:
1. A surrounding membrane
2. Protoplasm – cell contents in thick fluid
3. Organelles – structures for cell function
4. Control center with DNA
Cell Types:-
1. Prokaryotic
2. Eukaryotic
Prokaryotic cell
1. Do not have structures surrounded by membranes
2. Few internal structures
3. One-celled organisms, Bacteria
4. No membrane bound nucleus
5. Nucleoid = region of DNA concentration
6. Organelles not bound by membrane
Eukaryotic Cells
1.
Nucleus bound by membrane
2. Include fungi, protists, plant, and animal cells
3. Possess many organelles
“Typical” Animal Cell
http://web.jjay.cuny.edu/~acarpi/NSC/images/cell.gif
“Typical” Plant Cell
http://waynesword.palomar.edu/images/plant3.gif
Cell parts Organelles(Surrounding the Cell)
Cell Membrane
1. Outer membrane of cell that controls movement in and out of the
cell
2. Double layer.
Cell Wall:1. Most commonly found in plant cells & bacteria
2. Supports & protects cells.
3. Found in plants, fungi, & many protists
4. Surrounds plasma membrane
Cell Wall Differences
• Plants – mostly cellulose
• Fungi – contain chitin
Inside the Cell
Organelles
• Cellular machinery
• Two general kinds
– Derived from membranes
– Bacteria-like organelles
Nucleus
1. Directs cell activities
2. Separated from cytoplasm by nuclear membrane
3. Contains genetic material – DNA
4. Control center of cell
5. Contains
• Chromosomes
• Nucleolus
Chromosomes:
• In nucleus
• Made of DNA
• Contain instructions for traits & characteristics
Nucleolus
1. Inside nucleus
2. Most cells have 2 or more
3. Directs synthesis of RNA (RNA to build proteins)
4. Forms ribosomes
DNA
1. Hereditary material
2. Chromosomes
– DNA
– Protiens
– Form for cell division
3. Chromatin
Ribosomes
1. Each cell contains thousands
2. Make proteins
3. Found on ribosomes & floating throughout the cell
Nuclear Envelope
1. Separates nucleus from rest of cell
2. Double membrane
3. Has pores
Cytoplasm
1. Gel-like mixture
2. Surrounded by cell membrane
3. Contains hereditary material
Endoplasmic Reticulum
1. Moves materials around in cell
2. Smooth type: lacks ribosomes
3. Rough type (pictured): ribosomes embedded in surface
Mitochondria
1. Produces energy through chemical reactions – breaking down fats
& carbohydrates
2. Controls level of water and other materials in cell
3. Recycles and decomposes proteins, fats, and carbohydrates
Golgi Bodies
1. Protein 'packaging plant'
2. Move materials within the cell
3. Move materials out of the cell
Lysosome
1. Contain digestive enzymes
2. Functions
– Aid in cell renewal
– Break down old cell parts
– Digests invaders
Vacuoles
1. Membrane bound storage sacs
2. More common in plants than animals
3. Contents
– Water
– Food
– wastes
Plasma Membrane
1. Contains cell contents
2. Double layer of phospholipids & proteins
Cytoplasm
1. Viscous fluid containing organelles
2. components of cytoplasm
– Interconnected filaments & fibers
– Fluid = cytosol
– Organelles (not nucleus)
– storage substances
Cilia & Flagella
1.
Provide motility
2. Cilia
a. Short
b. Used to move substances outside human cells
3. Flagella
a. Whip-like extensions
b. Found on sperm cells
4. Basal bodies like centrioles
Centrioles
1. Pairs of microtubular structures
2. Play a role in cell division