Transcript I. Introduction to the Cell

I. Introduction to the Cell “With the cell, biology discovered its atom.” –Jacob
A. The cell is the smallest unit that can carry on all processes
of life.
1. make energy
2. produce waste
3. reproduce
4. respond to stimulus
5. evolve
B. Unicellular: one celled organisms…Protists and Bacteria
C. Multicellular: more than one celled organisms
D. Discovery of the cell was made possible by the
development of glass lenses.
1. Leeuwenhoek (Dutch)- first person to observe living cells
2. Hooke (English)- observed cork from the bark of an oak
tree.
a. The cells looked like empty compartments similar to
cells in a monastery so he named them “cells”
II. Formation of the Cell Theory
A. What is the cell theory?
1. all living things are composed of one or more cells
2. cells are the basic unit of life
3. cells only come from other cells
B. What they used to believe: Spontaneous Generation (living
things come from nonliving things)
1. mud produces fish
2. puddles of water produce microorganisms
3. rotting meat produces flies
4. stale bread produces mold
C. A series of experiments were conducted to prove
Spontaneous Generation wrong.
http://www.sumanasinc.com/webcontent/animations/content/scient
ificmethod.html
III. Cell Diversity
A. Shape
1. different shapes because they have different functions
a. nerve cells – long extensions to receive and give
messages
b. flat skin cells – to protect
c. white blood cells change shape so they can move
through narrow openings
B. Internal organization
1. Eukaryotic Cells
2. Prokaryotic Cells
nucleus
membrane bound organelles
no nucleus
no membrane bound
organelles
Ex: plants, animals, fungi, protists
Ex: Bacteria
C. Size: there is a limit of size due to the
speed at which materials need to get to
the center of the cell
D. Difference between plant and animal cells:
Plant cell
Animal cell
Thick rigid cell wall
No cell wall
Rectangular shape
No rigid shape (roundish)
Has chloroplasts
No chloroplasts
Large central vacuole
Some have small vacuoles
IV. Parts of the Cell
A. Cell Membrane
1. Separates the cell from its external environment
2. Gives shape and flexibility to the cell
3. Made of 2 layers (“phospholipid bilayer”)
4. Made of fats (phospholipids) and proteins
5. Cholesterol is also a part of the membrane
6. “Fluid Mosaic Model” is how scientists refer to its
structure
7. Drawing:
B. Cytoplasm: space within the cell excluding the nucleus
1. jelly like material that contains water, salt, sugars, fats
and proteins = cytosol
2. It is always moving
C. Organelles—“little organ”, each performs a specific activity
1. Refer to chart on next page.
The black stuff
Nucleus is purple,
cytoplasm is pinkish.
This is a lymphocyte
Contains DNA
Makes ribosomes
Protects the nucleus
Allows things to go in and out of the
nucleus
Not membrane
bound
Makes proteins
Rough because it is covered in ribosomes
Makes, packages, and transports protein
Packages and transports protein and fat
Where polysaccharides are made, packaged, and transported
Attaches carbohydrate tags to cell membrane proteins
Contains digestive enzymes
Breaks down foreign material,
old cell parts, and food.
Where food (glucose, fatty acids) is used
to make energy (ATP)
Tubulin…the protein that
makes up a microtubule
Hollow tube that makes up
cytoskeleton.
Gives cell its shape, helps in
movement and helps in cell division
Solid protein
thread that
makes up
cytoskeleton
Adipose Tissue (fat cells store fat
in a large central vacuole)
Organelle that stores food, waste,
and/or water.
Plants have 1 large one and
animals have many small ones.
Tail-like structure
Moves the cell
Tiny hairs on the
cell surface
Moves the cell OR
Moves things
around the cell