Download Cells Powerpoint

10/27/2009
Main types of Cells
•Prokaryotic cells
•No nucleus
•No organelles
•Very small in size
•Bacteria
•Eukaryotic cells
•Membrane bound nucleus
•Organelles of different functions
•Larger in size (some visible with no
microscope)
•All other living things
•The human body consists of 75 trillion cells
•Differences in cell shape make different functions
possible.
•A composite cell includes many different cell
structures.
•A cell consists of three main parts
•the nucleus
•the cytoplasm
•and the cell membrane.
•Within the cytoplasm are specialized organelles
that perform specific functions for the cell.
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The Cytoplasm
• Consists of a clear liquid portion, numerous
support molecules, and various organelles.
• Each organelle has its own specific job
1.Endoplasmic Reticulum
• Acts as passageways for materials to move
around the cell
• Come in Rough and Smooth varieties
• Rough E.R. has ribosomes
• Protein synthesis and modification.
• Smooth E.R. has no ribosomes
• Metabolism of drugs and alcohol.
2.The Golgi Apparatus
• Principle site of protein packaging,
modification, and delivery
• Molecules that enter the golgi apparatus
are normally sent to other cells.
cells
• The nuclear membrane, rough
endoplasmic reticulum, and golgi
apparatus are normally all connected
together by common membranes.
3.Mitochondria
• Site of cellular respiration
• Consists of two membranes
• Folded inner membrane
• Folds in inner membrane called cristae
• Smooth outer membrane
• Are thought to be “captured” bacterial cells
• Have own DNA
• Divide on their own on different time schedule
than rest of cell.
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Other Organelles
4. Lysosomes contain digestive enzymes to break up old cell
components and bacteria.
5. Peroxisomes contain enzymes that breakdown lipids, and
detoxify alcohol.
6. Microfilaments and microtubules are thin, threadlike
y
of the cell.
structures that serve as the cytoskeleton
7. Cilia and flagella are extensions from the cell
• Cilia – shorter
• Flagellum – Longer
8.Cell Nucleus
• Double-layered nuclear membrane
• Large nuclear pores
• Consists of
• Nucleolus
uc eo us - where
e e ribosomes
boso es form
o
• Chromatin – unwound DNA.
9.Chloroplast – Where photosynthesis
happens in plant cells
• Have two membranes
• Inside made up of Grana and Stroma
• Grana are stacks of Thylakoids
• Are also thought to be captured bacteria
cells
• Have own DNA
• Reproduce on their own
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10.Cell Wall – Protective outer covering of
plant cells, bacteria, and fungi.
• Made of cellulose in plants
• Gives plant cells shape and structure
• Inflexible.
• The cell membrane is the part of the cell that
determines what gets into and out of the cell.
• Diffusion, Osmosis, and Active Transport all occur
because of the cell membrane.
• The membrane consists of three main components
1.Phospholipids arranged into two layers (also
phospholipid
p
p bi-layer.
y
called the p
2.Proteins that perform a variety of functions
• Cell recognition
• Transport of materials
• Adhesion of cells to other cells
3.Cholesterol for maintaining rigidity of cells
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