On October 23rd, 2014, we updated our
By continuing to use LinkedIn’s SlideShare service, you agree to the revised terms, so please take a few minutes to review them.
Cells are the smallest working units of all living things.
All cells come from pre-existing cells through cell division.
Definition of Cell A cell is the smallest unit that is capable of performing life functions.
Examples of Cells Amoeba Proteus Plant Stem Red Blood Cell Nerve Cell Bacteria
Prokaryotes and Eukaryotes
Two Types of Cells
1 2 Prokaryotes Cell membrane Cytoplasm
They are the simplest form of life.
Do not have structures surrounded by membranes (organelles)
Few internal structures
They are unicellular _( One-celled organisms).
are the most complex form of life.
They have nucleus
Contain organelles surrounded by membranes
They are multicellular organisms (composed of many cells).
Most living organisms
Examples: animals and plants.
All cells are surrounded by a barrier called the cell membrane
They contain the molecule that carries biological information-DNA
Eukaryotic Plant Animal
Compare and contrast Prokaryotes vs. Eukaryotes Differences Prokaryote Differences Eukaryote Similarity
“ Typical” Animal Cell
“ Typical” Plant Cell
Differentia between animal and plant cells
Cell Parts Organelles CELL STRUCTURE AND FUNCTION
Cytoplasm lies between the cell membrane and nucleus and contains the organelles.
Cytosol is a gelatin like aqueous fluid that contains salts, minerals and organic molecules
Sites of chemical reactions that transfer energy from organic compounds to ATP
ATP- main energy source for cells
Cells with high energy requirements have more mitochondria ex: muscle and liver cells
Have 2 membranes
Smooth outer membrane serves as a boundary between the mitochondria and the cytosol
Inner membrane has many folds called Cristae – they enlarge the surface area for more chemical reactions
Have their own DNA ( for reproduction)
They are called the “ POWER HOUSE” of the cell
Not surrounded by a membrane
Made up of proteins and RNA
RNA is packaged into the ribosomes then transported to the cytosol
Some ribosomes are free
Some are attached to the endoplasmic reticulum
Protein is synthesized (produced) in the ribosomes
Proteins to be used in the cytosol – free ribosomes
Proteins to be exported or inserted in the cell membrane – ribosomes on the ER
System of membranous tubules and sacs
Intracellular Highway – molecules move from one part of the cell to another
2 types – rough and smooth
Rough covered by ribosomes – prominent in cells that make large amounts of proteins to be exported from the cell
Smooth – no ribosomes
Synthesis of steriods in gland cells
Regulation of calcium in muscle cells
Breakdown of toxic substances in liver cells
Processing, packaging and secreting organlle
System of membranes
Series of flattened sacs with convex shape
Works with the ER to modify proteins
Small spherical organelles
Enclose hydrolytic enzymes within single membranes
Digest proteins, carbohydrates, lipids, DNA and RNA
Digest old organelles, bacterias, viruses
Rare in plant cells
Maintains the shape and size of cell
Network of long protein strands
Not surrounded by a membrane
Participates in the movement of organelles
2 major components – microfilaments and microtubules
Microfilaments – threads made of actin (protein) – smallest strands
Microtubules – largest strands that are hollow tubes – help the cell divide by forming spindle fibers that extend across the cell
CILIA AND FLAGELLA
Hairlike organelles that extend from the surface of the cell
Assist in movement
Cilia – short and present in large numbers
Flagella – long and less numerous
Most prominent structure
Maintains its shape with a protein skeleton called the nuclear matrix
Double membrane – nuclear envelope
Inside the envelope – chromation (DNA & protein)
When the cell is about to divide it forms the chromosomes
Stores hereitary information in its DNA
RNA is copied from DNA
RNA travels from nucleus to the cytosol through small holes in the envelope – nuclear pores
Contains the nucleolus – the site where ribosomes are synthesized
Contains RNA to build proteins
Site where ribosome are synthesized
Most commonly found in plant cells & bacteria
Supports & protects cells
Usually found in plant cells
Contains green chlorophyll
Where photosynthesis takes place
Label the parts of the cell http://www.phschool.com/atschool/phbio/activities/cbd-3072/simbase.htm http:// www.harcourtschool.com/activity/cell/cell.htm
Ans. The cell structure and function
Muscle and liver 2
They enlarge the surface area for more
Endoplasmic Reticulum (ER) Hyghway Rought and smooth Ribosome Protein steroids
Shape and size
Microfilament & microtubule
Cilial and Flagella
DNE and protein
Nucleus Nuclear envelop DNE and protein Heridity Nuleoulus Ribosome
Name: ___________ Date :_____ 1/12/11
Quiz: cell structure and function
Multiple choice 1-22
No note can be used
Color and label parts of cell:
Animal and plant cells
The Human Cheek Cell http:// www.biologycorner.com/worksheets/cheekcell.html
The Human Cheek Cell
The Human Cheek Cell Procedure
1. Put a drop of methylene blue on a slide. Caution: methylene blue will stain clothes and skin.
2. Gently scrape the inside of your cheek with the flat side of a toothpick. Scrape lightly.
3. Stir the end of the toothpick into the stain and throw the toothpick away.
4. Place a cover slip onto the slide
5. Use the SCANNING objective to focus. You probably will not see the cells at this power.
6. Switch to low power. Cells should be visible, but they will be small and look like nearly clear purplish blobs. If you are looking at something dark purple, it is probably not a cell
7. Once you think you have located a cell, switch to high power and refocus.(Remember, do NOT use the coarse adjustment knob at this point)
The Human Cheek Cell Low High Sketch Scanning --- Sketch the cell at low and high power. Label the nucleus , cytoplasm , and cell membrane . Draw your cells to scale.
The Human Cheek Cell Questions
1. This cell is which cell type?
A. animal B. plant C. prokaryotic
2. The shape of this cell, overall, is:
A. round B. rectangular C. other
3. What stain did you use to see this cell type?
4. What material does this particular stain reveal?
5. Which organelles were apparent in this cell?
A. nucleus B. chloroplast C. central vacuole
6. Which cells are larger?
A. cheek B. bacteria
7. Is the cheek cell a eukaryote or prokaryote? How do you know?
8. Cheek cells do not move on their own, so you will not find two organelles that function for cell movement. Name these organelles.
The Human Cheek Cell Questions
1. Why is methylene blue necessary?
2. Cheek cells do not move on their own, so you will not find two organelles that function for cell movement. Name these organelles.
3. The light microscope used in the lab is not powerful enough to view other organelles in the cheek cell. What parts of the cell were visible?
4. List 2 organelles that were NOT visible but should have been in the cheek cell.
5. Is the cheek cell a eukaryote or prokaryote? How do you know
6. Keeping in mind that the mouth is the first site of chemical digestion in a human. Your saliva starts the process of breaking down the food you eat. Keeping this in mind, what organelle do you think would be numerous inside the cells of your mouth?
Surrounding the Cell
Outer membrane of cell that controls movement in and out of the cell
Inside the Cell
Directs cell activities
Separated from cytoplasm by nuclear membrane
Contains genetic material - DNA
Made of two layers
Openings allow material to enter and leave nucleus
Made of DNA
Contain instructions for traits & characteristics
Surrounded by cell membrane
Contains hereditary material
Moves materials around in cell
Smooth type: lacks ribosomes
Rough type (pictured): ribosomes embedded in surface
Each cell contains thousands
Found on ribosomes & floating throughout the cell
Produces energy through chemical reactions – breaking down fats & carbohydrates
Controls level of water and other materials in cell
Recycles and decomposes proteins, fats, and carbohydrates
Protein 'packaging plant'
Move materials within the cell
Move materials out of the cell
Digestive 'plant' for proteins, fats, and carbohydrates
Transports undigested material to cell membrane for removal
Cell breaks down if lysosome explodes
Membrane-bound sacs for storage, digestion, and waste removal
Contains water solution
Help plants maintain shape
Lies outside of the cell membrane
Helps support and protect the plant cell
Contains long chains of cellulose – hardens the entire structure
Pores in the cell wall allow ions to enter or exit the cell
Fluid filled organelles that store enzymes and metabolic wastes
Some vacuoles may make up 90% of the cell
Surrounded by 2 membranes and contain DNA
Some store starch or fats
Some contain pigments that absorb visible light – chlorophyll
Ex Chloroplasts – energy of sunlight is converted into chemical energy each chloroplast encloses a system of membranous sacs called thylakoids