Download What is a Cell?

Practical 1
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Multiple choice
Short answer
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Goals for Today’s Lab
1) Diversity of cells
2) Function of cell organelles
3) The Cell Cycle
What is a Cell?
Cells are the building blocks of the body
Form the tissues
There’s lots of
different kinds
of cells….
The Diversity of Cells
Epithelial Cells
Red Blood Cells
Skeletal
muscle cells
Cartilage cells
Gametes
Cell Anatomy – The Plasma Membrane
Separates the cell from outside environment
Selective permeability
Example:
H2O in/out easily
Glucose not as easily
Cell Anatomy - Cytoplasm
Contents of cell outside the nucleus
Contains the organelles
Cellular Anatomy - Nucleus
Control center of the cell
Contains the DNA
Surrounded by nuclear membrane
The Organelles
Machinery of the cell
Enable cells to perform functions
Ex: produce ATP, proteins
Kitchen Cell
Nucleus
Organelles
Organelles – The Ribosome
Location of protein synthesis
Free-floating or attached to endoplasmic
reticulum (Rough ER)
Organelles – Endoplasmic Reticulum
Rough ER stores and transports proteins
made on ribosomes
Organelles – The Golgi Apparatus
Flattened sacs that package proteins for
export out of the cell.
Organelles – Lysosomes
Contain digestive enzymes
Digest foreign substances entering the cell
Organelles – The Peroxisome
Contains the catalase enzyme
Controls the accumulation of H2O2 in body
Organelles – Mitochondria
Powerhouse of the cell
Produces ATP through breakdown of glucose
LAB ACTIVITY 1
Look at electron micrograph of cell
- Identify cell structures and organelles
Why do Cells Reproduce?
1. Growth
2. Replace old or damaged cells
Ex: Sunburn
How Often do Cells Divide?
It depends on the tissue
Some Constantly Divide
1) Skin Cells
2) Stomach Lining
Some Almost Never Divide
1) Nerve Cells
2) Muscle Cells
The Cell Cycle
Interphase
• Most of a cell’s life
• DNA in long strands
called “chromatin”
• Nuclear envelope intact
• DNA replication occurs
during “S Stage”
Mitosis
• Division of the nucleus
• One cell forms 2 identical daughter cells
• 4 stages
i) Prophase
ii) Metaphase
iii) Anaphase
iv) Telophase
i) Prophase
• Chromatin shortens
into chromosomes
• Chromosomes are 2
threads called “Sister
Chromatids” joined at
centromere
Centromere
i) Prophase, Cont.
•Nuclear envelope
breaks apart
•Sister chromatids
migrate to center of cell
ii) Metaphase
• Sister chromatids
line up along the
“metaphase plate”
• Mitotic Spindle
iii) Anaphase
• Centromere of sister
chromatids break
• Each chromosome is
pulled to opposite ends of
the cell by mitotic spindle
iv) Telophase
• Chromosomal movement
stops
• Chromosomes uncoil into
thin chromatin
• Nuclear envelope forms
• Cytokinesis
Cytokinesis
• Division of the cytoplasm
• “Cleavage furrow” squeezes cells apart
• Formation of two identical daughter cells
Daughter Cell
Cleavage Furrow
Daughter Cell
Mitosis vs. Meiosis vs. Cytokinesis
Mitosis: Division of the NUCLEUS in the cell
Meiosis: Division of GAMETES
Cytokinesis: Division of CYTOPLASM at the
end of Mitosis
Which stage of Mitosis are these
cells in?
LAB ACTIVITY 2: Identify the different stages
of mitosis on the cell slides under microscope
LAB ACTIVITY 3: Interactive Genetics
1.
2.
3.
4.
5.
6.
7.
8.
9.
Open up the C Drive
Go to “Program Files” folder
Open up “Interactive Genetics” folder
Double click on “Start.exe” file
Program should now open…..
Click on Topic II
Click on “Mitosis & Meiosis
Do Mitosis Movie
Do Problem 1