cell structure l3 biology chapter 1 section 2. what is a cell? smallest unit of life that can carry...
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Cell Structure
L3 BiologyChapter 1 Section 2
What is a cell?
• Smallest unit of life that can carry out all the functions of a living thing.
• Various sizes and shapes• Organism- living thing
– Unicellular – multicellular
Microscope Development
• 1665 – Robert Hooke named cell• 1674 – Anton von Leeuwenhoek -
looked at cells in pond water and blood and published his observations
Cell Theory Developed
• 1838 – Schleiden – all plants are made of cells• 1839 – Schwann – all animals are made of cells
• 1855 – Virchow – all cells come from pre-existing cells
Modern Cell Theory
• Cells are the basic units of all life.• All organisms are made of one or
more cells• All cells come from pre-existing
cells
Microscopes
• Hand lens• Compound light microscope
Cells from Labs:
Electron Microscope
• Uses electrons for energy source• Specimen must be killed• Transmission electron microscope
(TEM) – take pictures of slices of specimen
TEM Examples
•Scanning electron microscope (SEM) – take pictures of surface of specimen
SEM Examples
Types of Cells
• Prokaryotic– Simple cell– No membrane-
bound organelles– Chromosome not
contained in nucleus
– Small cells– Ex - bacteria
• Eukaryotic– Complex cell– Membrane-bound
organelles– Chromosomes
contained in nucleus
– Larger cells– Ex – all other
organisms
BASIC CELL STRUCTURES• Cell Membrane – Double layer of lipids
(fats) that lets stuff in and out of cell
Cytoskeleton
• Cell support• Anchors
organelles• Transports
materials• Helps cell
move
Nucleus
• Control center of cell• Contains Chromosomes
• Humans have 46 in each cell• Made of DNA
- control heredity- control protein synthesis
• Surrounded by double membrane – nuclear membrane
• Cell Membrane
Nucleolus
• Within nucleus• May be more than one• Makes ribosomes• Rich in RNA
Cellular Organelles – small, specialized structures in the cell
Ribosomes• Make proteins• Some are free,some are attached to endoplasmic reticulum.• Smallest
organelles
Endoplasmic Reticulum (ER)
• Transports materials through the cytoplasm
• Rough ER – have ribosomes attached– Transport proteins– Helps make membranes
• Smooth ER – no ribosomes attached– Makes lipids– Detoxifies wastes
Golgi Body
• Packages cell secretions• Makes lysosomes
– Contain digestive enzymes for breaking down food in food vacuoles and old, worn out structures – ex – sperm tail after fertilization.
Mitochondrion• Site of cellular respiration – food is
broken down to release energy.
Structures used for Movement
• Cilia • Flagella
Eukaryotic Cells include Plant and Animal Cells
ANIMAL CELL STRUTURE
Plant cells have some parts that animal cells don’t
• Cell Wall • Central Vacuole• Plastids
– Chloroplasts – Leukoplasts – chromoplasts
What animal cells have that plant cells don’t
• Centrioles – function during cell division
• Lysosomes – contain digestive enzymes
Now you are ready to have a test on parts of a cell and what they do:
• Make a chart like below: Cell part appearance
functionCell membraneCytoplasmEtc.
In addition, you should be able to name some differences between prokaryotic
and eukaryotic cells
Make a chart like this: Feature Prokaryotic
Eukaryotic
THE END
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