Download Notes: parts of a cell

Chapter 7 Notes:
Parts of the Cell
Robert Hooke
1635-1705
Cell Theory
1. All organisms are made of 1 or more cells.
These cells contain basic organelles.
2. The cell is the basic unit of organization of
organisms. Cells may develop specialized
functions based on the complexity of the
organism.
3. All cells come from pre-existing cells.
Cell Factoid of the Day
How long do cells live?
• White blood cells typically live only 7-8
hours. That’s a short life!
Cell Factoid of the Day
How long do cells live?
• Live bacteria have been found in Canada
that are over 500,000 years old. That’s a
looooong life!
Professor Eske Willerslev collecting soil samples in
the permafrost in the Yukon, Canada. Researchers
found half million year old bacteria in some of the
samples collected.
(Credit: Duane Froese, ScienceDaily Aug. 28, 2007)
Parts on the Outside
•
•
•
•
Cell membrane
Cell Wall (not on animal cells)
Cilia
Flagella
CELL MEMBRANE
• Boundary between cell and its external
environment
Two layers = lipid bilayer
CELL MEMBRANE
• Controls movement of materials (O2, H2O,
CO2, nutrients, waste) in and out of cell
CELL WALL (plants)
• Surrounds the cell membrane
• Adds strength and support to cell
http://www.aber.ac.uk/gwydd-cym/graffeg/biolgell/cludiant/collenchyma.jpg
CILIA
• Short hairs on outside
of the cell
• Provide movement
Lung Cilia
Image: Richard Superfine
FLAGELLA
• Long, whip-like tail on the outside of a cell
• Provides movement
Parts on the Inside
Cytoplasm, which contains…
• Nucleus (nuclear envelope, nucleolus,
chromatin)
• ER, Golgi Apparatus, Ribosomes
• Vacuoles, Lysosomes
• Chloroplasts, Mitochondria
• Cytoskeleton
CYTOPLASM
• Portion of the cell outside of the nucleus
• Jelly-like material suspends the other
organelles
Cell Factoid of the Day:
• Humans have about 50 trillion cells in their
bodies! = 50,000,000,000,000
• Blue whales have 80-100 quadrillion cells
in their bodies.
= 100,000,000,000,000,000!
NUCLEUS
• Control center for eukaryotic cells
• Contains chromosomes
http://www.emc.maricopa.edu/faculty/farabee/
Cell Factoid of the Day
Not all eukaryotic cells have one nucleus…
• Red blood cells (erythrocytes) discard their
nuclei at maturity, which makes them
better at carrying oxygen to body tissues.
Cell Factoid of the Day
Not all eukaryotic cells have one nucleus…
• Skeletal muscle cells and plasmodial slime
molds have many nuclei within a single
cell membrane.
CHROMATIN
• DNA wrapped around proteins
• Makes up chromosomes
Uncondensed Chromosome
Condensed Chromosome
NUCLEAR ENVELOPE
• Boundary between nucleus and cytoplasm
• Contains pores (holes) for materials to
pass in/out
http://acs.lbl.gov/ImgLib/
http://elliottcelltour.com/files/QuickSiteImages/Nucleus.jpg
NUCLEOLUS
• Produces the RNA that makes up
ribosomes
Photos by Mr. Stephens
RIBOSOMES
• Site where proteins are made (protein
synthesis)
• In cytoplasm or on rough ER
http://pbs.org
ENDOPLASMIC RETICULUM (ER)
• Folded membrane, which connects
nucleus to cell membrane
• Site for assembly and transport of proteins
ENDOPLASMIC RETICULUM (ER)
• ROUGH ER
• SMOOTH ER
GOLGI APPARATUS
• Packages and ships proteins out of or
inside the cell
http://www.ncbi.nlm.nih.gov/
http://kvhs.nbed.nb.ca/
https://www.msu.edu/~lupalisa/
LYSOSOMES
• Membrane-bound sac with digestive
enzymes inside
• Digests: worn-out organelles, food,
bacteria/viruses
http://www.medicine.mcgill.ca/dynhist/
VACUOLES
• Storage sac for: food, enzymes, water,
wastes, etc…
http://faculty.plattsburgh.edu/jose.deondarza/
http://www.bio.miami.edu/~cmallery/
MITOCHONDRIA
• Produces usable energy for the cell
• Breaks sugars (glucose) down for energy
(ATP)
http://porpax.bio.miami.edu/~cmallery/150/makeatp/makeatp.htm
CHLOROPLASTS (plants)
• Performs photosynthesis
• Converts energy from light to create
sugars and starches
CHLOROPLASTS (plants)
• Green because of pigment called
“chlorophyll”
Photosynthetic Sea slugs
http://www.seaslugforum.net/
MICROTUBULES
• Cytoskeleton
• Provides support for organelles and
maintain cell shape; used in cell division
http://elliottcelltour.com/
MICROFILAMENTS
• Cytoskeleton
• Provides support for cell
http://elliottcelltour.com/
http://tools.invitrogen.com/
CENTRIOLES
• Cytoskeleton (type of microtubule)
• Coordinate cell division (absent in most
plant cells)
Tuesday, 11/20/2012
Objective: SWBAT identify and describe the
functions of major cell parts.
Warm-up Questions:
1. What is the relationship between you and
your cells?
Monday, 11/21/2011
Objective: SWBAT identify and describe the
functions of major cell parts.
Journal Question: Describe the process of
assembling and transporting a protein in the
cell. Be sure to include all of the organelles
involved.
Tuesday, 11/22/2011
Objective: SWBAT identify and describe the
functions of major cell parts.
Journal Question: Draw and label a
nucleus. Be sure to include all of the parts
that you’ve learned about.
Worksheet 7-2: Scoring
# wrong/skipped
Score (out of 15 possible)
0-2
15
3-4
14
5-6
13
7-8
12
9-10
11
11-12
10
13-14
9
15-16
8
17-18
7
19-20
6
21-22
5
Each cell diagram
on the front page
counts as a single
question.
Completion grade
only (are all of the
parts labeled?)
Wednesday, 11/23/2011
Objective: SWBAT identify and describe the
functions of major cell parts.
Journal Question: none
Analogies…
… should focus on function, not structure
… should be written in complete sentences
… should be clear and understandable.
meow