Transcript CELL STRUCTURE & FUNCTION Ch. 7, Sec. 1-2 Pages 169-181

CELL
STRUCTURE &
FUNCTION
Ch. 7, Sec. 1-2
Pages 169-181
Section 7.1, Life is Cellular
I. Discovery of the Cell
A.
Robert Hooke, 1665
- First to use a Compound Microscope
to look at “cells.”
1.
A compound microscope has
two lenses.
(Objective lens & Eyepiece)
2.
Looked at a thin slice of cork
which had many “little rooms.”
B.
Anton van Leeuwenhoek, 1674
– Used a simple microscope
(one lens) to look at pond water.
– He saw tiny living organism which
he called “animalcules.”
II. The Cell Theory
A. What is a cell?
- The basic unit of life.
B. Schleiden & Schwann
– German scientists who stated the cell theory:
1. All living things are made of cells.
2. Cells are the basic units of structure &
function.
3. All cells are produced by existing cells.
IV. Prokaryotes and Eukaryotes
A. Prokaryotic Cells
– Cells that do not contain a nucleus.
– DNA is free to float inside the cell.
– All bacteria are an example of
prokaryotes.
B. Eukaryotic Cells
- Larger & more complex
- Have a nucleus that contains the DNA
- Have many “specialized” internal
structures contained within a membrane
- May live as single cells or make up
multicellular organisms.
Section 7.2 Eukaryotic Cell
Structure
I. Types of Eukaryotes.
- Plant & Animal cells
II.
Organelles
- Membrane-bound structures that act like
individual organs.
- Each carries out a specific function.
III.
Cytoplasm
- Area between the nucleus and cell
membrane.
- Contains a fluid/jelly-like substance which
allows easy movement of wastes and raw
materials in and out of the cell.
IV. Parts of a Eukaryotic Cell
A. Nucleus
1. Contains all the DNA within a cell.
2. Surrounded by the “Nuclear Envelope.”
- Membrane that protects the
inside contents and also
allows for the passage of
materials in and out of the
nucleus such as RNA.
3. Nucleolus
- Center region of the nucleus where DNA is
located and the production of ribosomes
begins.
4. Chromatin
- Form DNA is in when a cell is not dividing.
- DNA wrapped around DNA.
- “Looks like thin tangled/bound shoe laces.”
5. Chromosomes
- Form DNA is in when a cell is dividing.
- “Looks like single thick shoe laces”
B. Ribosomes
1.
Small grain-like particles of RNA
inside the cytoplasm.
2.
Located throughout the cell
3.
Produce proteins from information
within DNA.
C.
Endoplasmic Reticulum
1. System of passageways that
transports proteins & other materials
throughout the cell.
2. Two types of E.R.
a. Rough E.R.
- Is covered with ribosomes which
produce proteins.
b. Smooth E.R.
- Mainly responsible for transportation
and finishing the production of proteins.
D. Golgi Body (Golgi Apparatus)
1. Proteins from the E.R. are
transported here next.
2. Modifies, or packages proteins
and other materials before they
are secreted outside of the cell.
- Puts the “finishing touches” on
proteins.
E. Lysosomes
1.Small organelles filled with digestive
enzymes.
- Break down food molecules that can
be used by the cell as well as waste
products.
F. Vacuoles
1. Sac-like structures that store water,
food and/or waste products.
- Extremely important in water storage for
plants.
G. Mitochondria
1. Organelles that convert chemical energy
stored in food particles into a more useful
form.
2. Are enclosed by two membranes:
a.
Outer
- Protects the inside of the
mitochondria and allows materials to
move in and out.
b.
Inner
- Inside membrane where energy
production occurs (ATP).
H. Chloroplasts
1. Found only in plant cells.
- Capture energy from sunlight and convert
it into chemical energy in the process
known as “PHOTOSYNTHESIS!”
a. Creates “glucose.”
I. Cell Barriers
A. Cell Membrane
- Found in plants, animals & bacteria.
- Is a semipermeable lipid bilayer.
- Controls what goes in and out of a cell.
B. Cell Wall
- Found in plants, algae, fungi & bacteria.
- Provides support and protection to the cell.
- Made mostly of the Carb. Cellulose.
Cell Membrane Structure
Cell Wall
Cytoskeleton
• Network of protein filaments that supports
the shape of the cell and allows for
movement throughout cell.
– Composed of microfilaments and
microtubules.