Transcript Adv Biology

Adv Biology
Chapter 4 Cells
Microscope
• The biologist’s tool is the microscope
• Until developed, only the single egg
had been observed
• Hooke looked at dead plant bark, cork,
and it reminded him of rooms in a
monastery and he called them cells
• Later we would learn that what he saw
was the cellulose cell walls of plant
cells
Microscopes have come a long
way!!
Anton van
Leeuwenhoek
(1670)
Robert Hooke
(1665)
Robert Brown (1831)
Matthias Schleiden
(1838)
Theodor Schwann
(1838)
Johannes Purkinje
(1839)
Rudolf Virchow
(1858)
1) first to use the term "protoplasm"
2) while studying cork, he was the first to use
the term "cell"
3) stated that all new cells come from other
living cells
4) studied many microscopic organisms using a
strong simple microscope
5) stated that all plants are composed of cells
6) stated that all animals are composed of cells
7) "discovered" the nucleus
Answers to "Cell Scientists
Matching" :
1) J. Purkinje
2) R. Hooke
3) R. Virchow
4) A. von Leeuwenhoek
5) M. Schleiden
6) M. Schwann
7) R. Brown
Cell Theory
1. all living things are made up of cells &
the products of those cells
2. all cells carry out their own life functions
3. new cells come from other living cells
Cell Theory
• #1 & 2 are primarily a combo of Schleiden &
Schwann's research, & statement #3 is Virchow's
idea.
• In 1838 Schleiden proposed that all plants are
composed of cells; together with his friend Theodor
Schwann he formulated the cell theory of life.
Schleiden observed various cell structures and
activities such as protoplasmic streaming.
• Schleiden also found that certain fungi live on or
within the roots of some plants. This relationship
between fungi and plants, called mycorrhiza ("fungi
roots"), has since been shown to be very common
and extremely beneficial to both organisms.
Different shapes, different
functions
Cell
Three major areas of eukaryotes
– Cell or plasma membrane
– Cytoplasm
– DNA
Typical cell
Plasma Membrane
Mitochondria
• Mitochondria—where
energy is produced as
ATP
• Power house!!
Ribosomes and RER
1. Ribosomes where proteins
are made, may
be in
cytoplasm or
attached to
RER (2)
3. RER – rough
endoplasmic
reticulum
SER and ER
1. Rough
endoplasmic
reticulum—series of
channels though
out the cytoplasm.
Have ribosomes
attached
3. Smooth ER does
not have ribosomes
attached
Golgi Bodies
Golgi bodies
Special packaging organelle for making
enzymes for use in the cell, or for export
as hormones in glands
Centriole-involved during
mitosis
Nucleus
1. nuclear membrane
3. nuclear pores
2. nucleolus
4. chromatin
Chromatin ~ Chromosomes
1. Untwisted DNA is chromatin when cell is
not in mitosis
2. Twisted tightly and coiled until they can be
seen—chromosomes. Seen during mitosis
Chromosomes
Microvilli
Finger-like projections that increase surface
area along the cell membrane
Why is little better than big?
• As cells increase in size, the surface area to
volume ratio is diminished. Big cells cannot
get enough food or get rid of wastes.
• One reason why cells may divide—to return
to a greater surface area volume ratio.
Food vacuoles – store and where
enzymes break down food to
yield ATP’s
Compare a plant and animal cell
Contrast animal and plant cell
ORGANELLE
ANIMAL CELL
PLANT CELL
centrioles
visible
none (not visible)
cell wall
none
present
chloroplasts
none
present
vacuole
small
large
Match
cell membrane
cell wall
chloroplast
centrioles
centrosome
cytoplasm
endoplasmic
reticulum
golgi apparatus
lysosome
mitochondria
nuclear membrane
nucleolus
nucleus
ribosomes
vacuole
1. liquid inside the cell, mostly water
2. made of lipids & proteins, it is the boundary of the
cell; it controls what substances enter or leave the cell
3. "control center of the cell" where genetic material
(DNA) is found
4. nonliving border that surrounds plant cells, made of
cellulose
5. very small organelles that are the sites of protein
synthesis
6. system of tubes through the cytoplasm involved in
transporting materials
7. a flat stack of tubes involved in "packaging"
materials that will exit the cell
8. site of cellular respiration (where energy is released
from nutrients)
9. storage sac for water or other materials
10. controls what enters or exits the nucleus
11. dark round structure within the nucleus that
produces ribosomes
12. specialized vacuole that stores digestive enzymes
13. structure in animal cells involved in cell division
14. spherical structure that contains the centrioles
15. site of photosynthesis in plant cells
ANSWERS to "Organelle
Functions" Matching :
1. cytoplasm
2. cell membrane
3. nucleus
4. cell wall
5. ribosomes
6. endoplasmic reticulum
7. golgi apparatus
8. mitochondria
9. vacuole
10. nuclear membrane
11. nucleolus
12. lysosome
13. centrioles
14. centrosome
15. chloroplast
Study!!!