Transcript Ch 4 Cells
Chapter 4 - Cell Structure and Function
The printed out notes are more detailed than these slides, you are expected to read the chapter and your notes - anything is fair game on the test, but the cell chapter is largely review.
Lab: microscopes and membranes Thurs: 10/9
A. The Cell Theory
1.
Every living organism is made of one or more cells
.
2.
The cell is the basic unit of structure and function.
It is the smallest unit that can perform life functions.
3. All cells arise from pre existing cells.
*Why is the Cell Theory called a Theory and not a Fact?
Cells need a
large surface area to volume ratio
If there a person was at the very center of each house and accidently started a fire, the person in which house would have a better chance of escaping?
Figure 4.3
Early Contributions
Hooke Leeuwenhoek Schleiden Schwann Virchow
http://htwins.net/scale2/
B. ALL CELLS HAVE:
1. Cell Membrane a) Phospholipid Bilayer (double layer) b) Proteins c) Carbohydrates
2. Genetic Material
3.
Cytoplasm (cytosol)
ORGANELLES float within cytoplasm and perform specific functions
Prokaryote Cells
Figure 4.4a
Eukaryotes
Endosymbiosis :
All organelles seem to share many properties with bacteria. Lynn Margulis proposed:
endosymbiosis hypothesis: that ancient colonization of large bacteria (became the eukaryotic cell) engulfed smaller bacteria (became the mitochondria, chloroplast, etc.
) Symbiosis = "living together".
*Mitochondria & Chloroplasts have their own DNA Animation at Microbiological Concepts
https://www.youtube.com/watch?v=3ESXvLHceDc
Endosymbiosis Theory
that ancient colonization of large bacteria (became the eukaryotic cell) engulfed smaller bacteria (became the mitochondria, chloroplast, etc.
)
http://www.youtube.com/watch?v=-FQmAnmLZtE
In your notes: Create a diagram comparing prokaryotic and eukaryotic cells. Include examples of each and anything you can remember When done, use ch 4 to label the pictures on your notes outline handout pg 65 and 68
Prokaryote
No Organelles Simple Mostly single cells Archaea and bacteria both Cells DNA Cytoplasm Plasma Membrane Ribosome Cell wall
Eukaryote
Membrane Bound Organelles Nucleus Complex Specific in function Multicellular Plants, Animals, fungi
Quick Recap.......
1. What are the two main types of cells?
2. Which one is larger? 3. Which one does not have a membrane bound nucleus?
4. What are the three main parts of the cell (that all cells have)?
5. What are the 3 components of the cell theory?
6. What theory best explains how eukaryotes evolved? Label the pictures on the top of your notes outline: use 65, 68-69 to help
Prokaryotic or Eukaryotic? 1 2
1. Has membrane bound organelles 2. Includes plant and animals cells 3. Bacteria
P
4.
E E E
5.
P
6. Has no organelles
P
cell biology is a huge area, and is divided into many branches that biologists specialize in...
1) Oncology 2) Microbiology 3) Genetics 4) Paleobiology 5) Pathology ............to name a few Here's an older video that compares prokaryotes and eukaryotes and discusses how cells evolved, film by the Phoenix Learning Group (17 minutes) And a shorter video on the main parts of The Cell
The Parts of the Cell
Cell Diagram Directions:
1.
You will get a picture of a animal or plant cell, label the cell.
2.
3.
4.
label as many parts as you can remember Then look in your book to label the rest Write a 2-5 word description of the function of each part
• • • • II. Nucleus:
Nucleoplasm
: semifluid matrix
Chromatin
: uncoiled, fluid DNA and proteins
Chromosomes
: coiled, rodlike DNA structures
Gene
: unit of heredity located on DNA • •
Nucleolus
: dark region of chromatin where
rRNA
joins with
proteins
to form ribosomal subunits (parts to make ribosomes)
nuclear envelope
contains things to enter and exit
nuclear pores
for some
III. Endomembrane System:
Includes: a.
Nuclear envelope b.
Membrane of the ER c.
Golgi apparatus d.
Several types of lysosomes
I am a reticulated python. Ask me what I have to do with the endoplasmic reticulum.
A. Nuclear Envelope/ Membrane:
RNA leaves nucleus to instruct production of proteins
B. Endoplasmic Reticulum (endoplasm= "within cytoplasm", reticulum= "little net" --divides cell into compartments --channels molecules through the cell's interior, like a little highway, make vesicles Rough ER --has
ribosomes
--functions in Figure 4.10a
protein
synthesis -- ER transports newly assembled proteins to the
Golgi Apparatus
Smooth ER --no ribosomes --mostly contains enzymes that act in
lipid
hormones like estrogen and testosterone) Vary depending on location synthesis (such as
C. Golgi Apparatus: Delivery System -flattened stacks of membranes -functions in collection,
modifying
,
packaging
and
distributio
n of molecules made in the cell and used elsewhere unprocessed proteins enter the front end ( cis ) near the ER, and are exported near the cell membrane, at the back end ( trans ) --the folded stacks are called
cisternae
Jobs of the Golgi Apparatus (aka Golgi Complex)
1. separates proteins according to their destinations 2. modifies proteins (adds sugar and makes glycoproteins) 3. packages materials into
vesicles
which are exported outside the cell -
secretion
Lysosomes - Intracellular Digestion Centers
--contain high levels of degrading
enzymes
(to "lyse" means to dissolve) --recycle old and worn out cell parts sac”
apoptosis
"suicide -digest other particles taken in by
phagocytosis
--this "food" is stored in food vacuoles, the lysosomes fuse with the vacuoles and release digestive enzymes
Lysosomes - Intracellular Digestion Centers
TAY-SACHS disease
– What do lysosomes have to do with this deadly disease?
Article and Video on Tay Sachs http://6abc.com/archive/9036458/ https://www.youtube.com/watch?v=RzEpkBU-ITA
Tay-Sachs disease is caused by the absence or significantly reduced level of a enzyme called beta-hexosaminidase (Hex-A). Normally, Hex A is a digestive enzyme that is part of the lysosome. Without the correct amount of the Hex-A enzyme, a fatty substance or lipid called GM2 ganglioside accumulates abnormally in cells, especially in the nerve cells of the brain.
Ribosomes - Sites of Protein Synthesis
-each is composed of two
subunits
, one large and one small -mRNA is "read" by the ribosomes and amino acids are assembled into proteins -ribosomes are manufactured by the nucleolus , assembles by ER --
polyribosomes
– strings of ribosomes in the cytoplasm that work to make a protein
Free vs Bound Ribosome
Free ribosomes: produce proteins that are used by the cell. - ex: for metabolism of food. Bound ribosomes: produce proteins that are transported out of the cell. - ex: for a specific function, such as digestive enzymes and polypeptide hormones.
Mitochondria
--contains its own DNA, support for Endosymbiosis • Theory mitochondria divide before cell division, they are not synthesized like other cell parts --
function:
store energy for cell use. Energy is stored in the form of
ATP
adenosine triphosphate -2 membranes, one smooth outer membrane, and an inner membrane folded into layers called
cristae
--Cristae has two compartments: the
matrix
intermembrane space and the
What happens if your mitochondria don’t work?
Mitochondrial Disease Video Why is mitochondrial disease so devastating to children?
Consider the mitochondria have their own DNA separate from the parental DNA. How could you cure this disease?
https://www.youtube.com/watch?v=6_ylLEhRG30
Focus on Plant Cells
Chloroplasts - Where Photosynthesis Takes Place Plants only
--has its own DNA, like mitochondrion --functions : to convert light energy to
carbohydrates
--carbohydrates then broken down in mitochondria to produce ATP
Parts of chloroplast --
thylakoids
--
Grana :
are the individual disk shaped compartments stack of thylakoids --
stroma
is the fluid surrounded the thylakoids *Chloroplasts are a type of
plastid Chromoplasts –
red, yellow and orange pigment
Leucoplasts –
colorless (potatoes)
Cytoskeleton- support system a. Microfilaments (
now called
actin filament ) –
occur in bundles, form tracks within the cell for the movement of organelles, used to form
pseudopod
s (ameba) b.
Intermediate filaments
- support membrane, cell to cell junctions c.
Microtubules -
the
spindle
(little pipe) radiate from the
centrosome
during cell division
-
form
Centrioles
division – used during cell to move and separate chromosomes, only found in animal cell
Cytoskeleton
How do cells maintain their shape?
How do they move?
- pseudopod - cilia - flagella
Pseudopod
– extensions of the cell that allow for movement (ameba), depend on actin filaments
Cilia
( hair ) &
Flagella
--function in movement ( whip ) -- 9 + 2 Arrangement of microtubules http://www.youtube.com/ watch?v=7pR7TNzJ_pA
Hey....remember enzymes?
The Peroxisome
Found in plant and animal cells, this organelle plays a critical role in normal cell functioning. In human cells, peroxisomes house some sixty enzymes, involved in metabolic processes such as bile acid, cholesterol, and plasmalogen biosynthesis, as well as ß-oxidation peroxisome produces hydrogen peroxide as a by-product of its normal function. -To neutralize this potentially toxic compound, a peroxisome imports the hydrogen peroxide metabolizing enzyme
catalase
, from the cytosol of the cell. Catalase converts hydrogen peroxide to water and oxygen
Vacuole
-- mainly storage or specific functions (contractile vacuole, fat vacuole) -- Plant cells have a
CENTRAL VACUOLE
and help to maintain hydrostatic pressure - used for storage
QOD:
1. What does the cell theory state? 2. Explain why cells are so small using the idea surface area- to- volume ratio. 3. Compare and contrast plant and animal cells
use a graphic organizer: (venn, tree map, etc) •Plant Cell •Animal cell •Eukaryote •Plasma Membrane •Nucleus •Ribosome •ER •Mitochondria •Chloroplast •Cell wall •Cytoplasm •Golgi Apparatus •Vacuole •Centrioles •Fern Cells •Muscle Cells •Human Cells
Plant Animal
Tree Map
Double Bubble (like a venn diagram)
vacuole Chloroplast Fern Cell wall
Plant Cell
Eukaryote centrioles Nucleus Mitochondria Cytoplasm Plasma Membrane Ribosome ER lysosome Golgi apparatus
Animal Cell
Muscle cells humans
Plant Cell
vacuole Cell wall Chloroplast Fern
Eukaryote
Nucleus Mitochondria Cytoplasm Plasma Membrane Ribosome ER lysosome Golgi apparatus
Animal Cell
centrioles Muscle cells humans
QOD: Proteins in the Cell
What parts of the cell are involved with protein production and what role does each part play? Most of the Endomembrane: • Nucleolus • Rough ER • Golgi • Vesicles • Free Ribosome
Mini Quiz
1. What part of the cell produces vesicles for export?
2. What part of the cell makes proteins?
3. What part of the cell produces ATP?
4. What part of the cell transports materials throughout the cytoplasm?
5. What part of the cell has a cis and a trans face? https://www.youtube.com/watch?v=1Z9p qST72is&feature=youtu.be
a. ________________ b. ________________ c. _________________ d. _________________ e. _________________ f. __________________ f.
Find the: a. Nucleolus b. Centriole c. Vesicle d. Smooth ER e. Lysosome
Figure 4.7b
What is this structure?
What is this structure?
Terms / Concepts for Show, Don't Tell
cell_theory mitochondria chloroplast prokaryote protein_synthesis eukaryote nucleus lysosome ribosome endoplasmic_reticulum cytoskeleton golgi_apparatus enzyme messenger_RNA chromatin phospholipid_bilayer cilia flagella microscope peroxisome
Single Cheek Cell - at different illuminations