Transcript 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-thin flexible
barrier around the cell
• Cell wall- support and protect
(most common in plant cells)
• Cytoplasm- material inside of the
cell membrane
More Structures:
• Nucleus: contains genetic material
and controls the cell’s activities
– Chromatin: DNA bound to proteins
– Chromosomes: condensed DNA visible
during cell division
– Nucleolus: ribosome assembly occurs
here
– Nuclear envelope: double membrane
protecting the nucleus
Cytoskeleton:
microtubules/microfilament
**Microtubules:
think train tracks
moving things
along
**Microfilaments:
think steel beams in
a building holding
everything up
• Ribosomes:
manufacture
protein
• Endoplasmic
Reticulum:
rough = protein
modification;
smooth =
synthesis of
lipids/
membrane
formation
Lysosome:
enzyme filled to
break down lipids,
carbohydrates and
proteins
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!!
Mitochondria: (own DNA from
Mom) energize the cell
Which cell has the most
mitochondria?? Your heart!
• “Endurance” is a
function of how
many
mitochondria are
in your cells!