Download Biology- ch. 7

Biology- ch. 7
“Cells- the basic unit of all
forms of life”
Robert Hooke
• 1665- coined the
term “cell” to
describe the tiny
rooms that he
noticed inside of
cork
• Made a simple
microscope of
his own to use
Anton van Leeuwenhoek
• Dutch businessman
• Used a microscope to study
nature in 1600’s in Holland
• He was the first person to see
living organisms in a drop of
water
Cell Theory
• All living things are composed of cells
• Cells are the basic units of structure
and organization in living things
• New cells are produced from existing
cells with cells passing copies of their
genetic material down to their daughter
cells
Microscopes:
1) Compound
light
microscope:
use lenses to
magnify an
image
2) Scanning
Electron
Microscope:
magnets
aim
electrons at
the sample
Prokaryotic Cells vs.
Eukaryotic Cells
• Prokaryotic: contain cell
membranes and cytoplasm but do
not contain nuclei; example:
bacteria
• Eukaryotic: contain nucleus and
specialized cell parts
Cell Structures:
• Cell Membrane – (all cells)
thin flexible barrier around the
cell.
“gate-keeper”
• Cell wall - support and protect
(plant, fungus & bacteria cells)
• Cytoplasm – “cell gel” material
inside of the cell membrane. Most
chemical reactions take place
here
Cytoplasm structure
• Cytoskeleton –
• framework for
cell and anchor
organelles in
place.
• Made up of
microtubules and
microfilaments
working together
Cytoskeleton:
microtubules/microfilament
A
**Microtubules:
think train tracks
moving things
along
**Microfilaments:
C
B
D
think steel beams in a
building holding
everything up. Also
function in movement
for unicellular
organisms
A
B
C
E
D
More Structures:
• Nucleus: contains genetic material
and controls the cell’s activities
– Chromatin: DNA bound to proteins
– Nucleolus: ribosome assembly occurs
here
– Nuclear envelope: double membrane
protecting the nucleus
– Nuclear pores: holes in nuclear envelope
that control substances passing into and
out of nucleus
• Ribosomes:
manufacture protein
• Endoplasmic
Reticulum: Maze-like
structures
• Rough ER = “rough”
b/c has ribosomes on it;
function is protein
modification;
• Smooth ER = synthesis
of lipids/ membrane
Lysosome:
Animal cells only
enzyme-filled to break
down lipids,
carbohydrates,
proteins and worn cell
parts
Sometimes AKA
“suicide sac”
Golgi Apparatus:
modification of
protein,
packaging
Vacuole: think storage closet
full of water, proteins, salts,
and carbohydrates
**Larger vacuole
found in plants!
Chloroplast: Use energy from the
sun to make food for plants
(photosynthesis)
Mitochondria: releases energy
from sugars to power the cell
(has its own DNA from Mom)
•Which cells in your
body have the most
mitochondria?
•Your heart muscle
cells!
• “Endurance” is a
function of how
many
mitochondria are
in your cells!