1. Cell Structure and Function
Chapter 7
Cell Structure and Function

2. What does it mean to be alive?
Ability to grow and develop
Ability to reproduce
Ability to adapt to the environment
Have structure
Chapter 1 review

3. Components of Cell Theory
All living things are composed of cells
Cells are the basic unit of structure and function in living things
New cells are produced from already existing cells

4. Microscopes First microscopes were single lens (think of glasses)
Compound microscope (multiple lenses)
Limited on detail and resolution because light is scattered as it passes through matter
Electron Microscope – beam of electrons is aimed at the cell
Electrons are not easily scattered
1000x resolution of best light microscope
Limitation – subject can’t be alive since it is done in a vacuum

5. Two Types of Cells
Prokaryote
Eukaryote

6. Prokaryote Bacteria and other simple cell organisms
Very basic cells with no membrane bound organelles
DNA is not separate from the rest of the cell
Maximum size of bacteria is about mm (1 m)

7. Eukaryote
Complex unicellular organisms and all multicellular organisms
Cells that contain membrane bound organelles
The DNA is separated from the rest of the cell by a nucleus
Maximum size is 0.1 mm (100 m)  larger than prokaryotes

8. Quick Check Classify each as eukaryotic or prokaryotic Human Bacteria
Algae
Mold
Virus

9. Cell Structure and Function

10. Organelle Translates to mean “little organ”
A structure inside a cell that has a specialized function
Machinery of a cell
Ex: Nucleus, chloroplast, cell wall

11. Cell Membrane Found in plant and animal cells Function:
Protection
Allows molecules to pass through
Semipermeable: only certain molecules can pass through

12. Cell Wall Made of cellulose or chitin
Found only in plants, fungus, bacteria, and some protists.
Function:
Provide support

13. Cytoplasm Fluid that surrounds the organelles and fills the cell
Function:
Provide a medium for chemical reactions to occur

14. Nucleus “Brain” of the cell Function: Found in Nucleus:
Control the activity of the cell
Store genetic information (DNA)
Found in Nucleus:
Chromatin – structure of DNA
DNA/Genes – the genetic message used to make proteins

15. Nucleolus Function: Found within the nucleus
Where the ribosomes are made

16. Ribosomes One of the few organelles also found in prokaryotic cells
Not membrane bound
Function:
Makes proteins according to RNA
RNA (ribonucleic acid) – carries the instructions for making protein from DNA in nucleus to the ribosome

17. Mitochondria The “powerhouse” of the cell
Present in all eukaryotic cells
Function:
Site of cellular respiration
Production of energy for cell
Glucose  CO2 + water + energy

18. Chloroplast Found only in plant cells and some protists
Contain green pigment called chlorophyll
Function:
Site of photosynthesis
Produces sugar from carbon dioxide, water, and light energy

19. Endoplasmic Reticulum
Two types – rough and smooth
Rough E.R.:
Has “bumpy” look because of the presence of ribosomes
Function: produce and transport proteins
Smooth E.R.:
Looks smooth, no ribosomes
Function: produce and transports lipids

20. Golgi Apparatus Flattened membrane sacs Function:
Packages, modifies, and transports the protein for specific uses
Produces vesicles (transport) and lysosomes (contains enzymes)

21. Vacuole Plants have large permanent vacuoles
Animals have smaller temporary vacuoles
Function:
Storage of materials such as water, salts, proteins, lipids, carbohydrates, and waste products.

22. Lysosomes Sacs containing enzymes Function:
Digest food and old cell parts
When the cell gets worn out the lysosome will burst and digest the whole cell

23. Cytoskeleton Made up of microtubules and microfilaments Function:
Helps maintain cell shape
Responsible for many forms of cell movement including organelle movement

24. Movement Cilia: Flagella Short, hairlike structures that move the cell
Ex. Paramecium
Flagella
A long threadlike structure used to propel the cell
Ex. Sperm, Euglena

25. Levels of Organization within and Organism
Cell – basic unit of life
Tissue – a collection of cells that work together for a common purpose
Organ – two or more tissues acting together
Organ system – a group of organs that work together in a system

26. Exit Slip 1 2 3 7 4 5 6