1. Cell Structure & Function

2. Life is Cellular

3. A little history…
1600s: van Leeuwenhoek used microscope to study nature
1665: Hooke used microscope to look at plant tissue & cork; called them “cells”
1838: Schleiden concluded that all plants
were made of cells
1839: Schwann concluded that animals are made of
cells
1855: Virchow studied cell reproduction and concluded that cells come from cells

4. The basic unit of ALL living organisms.
What is a cell?
The basic unit of ALL living organisms.
Scale of Life

5. Cell Theory All living things are composed of cells.
Cells are the basic units of structure & function in living things.
New cells are made from existing cells.

6. Types of cells:
Prokaryotes
Eukaryotes

7. Prokaryotes Unicellular No nucleus Asexual reproduction
Example: bacteria

8. Eukaryotes Unicellular or multicellular Nucleus present
Organelles present
Sexual reproduction
Examples: plants, animals, people

9. Prokaryotes & Eukaryotes have:
Cell membrane
Cytoplasm
Ribosomes
Cell wall (plants only for Eukaryotes)

10. Cell membrane The “skin” of the cell.
Protects cell from outside environment.
Regulates flow of water, nutrients & waste.

11. Cytoplasm Material inside the membrane (not including the nucleus).
Contains many important structures.

12. Other cell parts to know:
Cell Wall
Found outside cell membrane
Supports & protects cell
Plant cells & some bacteria
Cytoskeleton
Maintains shape
Movement
Nucleus
Organelles

13. Nucleus The “brain” of the cell. Controls cell functions.
Contains DNA.
Surrounded by nuclear envelope.

14. Organelles ”Little organs” Specialized parts of the cell.
Examples: ribosomes, mitochondria, chloroplasts, vacuoles

15. Cell Transport

16. Cell Membrane Functions: Provides protection and support.
Regulates what enters
and leaves the cell.
Takes in food and water.
Eliminates waste.
Allows the cell to maintain homeostasis.

17. The cell membrane is semi-permeable.
Some substances can pass through it, while others cannot.
Most biological membranes are semi-permeable.

18. Parts of the Cell Membrane
Phosopholipid bilayer: the core of the membrane; forms a strong barrier between the cell and the outside
Protein channels: form pumps to move material through membrane
Carbohydrates: identify the cell; on the outside

19. Concentration
How many molecules are in a given volume. (How crowded the molecules are.)
Concentration = Amount of solute
Volume of Solution
Every cell is surrounded by liquid and has a liquid interior (cytoplasm) that are solutions of many different substances.
High Concentration
Low Concentration

20. Passive Transport: movement from an area of high concentration to areas of lower concentration (getting less crowded); does not require energy
Diffusion
Facilitated Diffusion: molecules that are too large to pass through the cell membrane go through protein channels
Osmosis: the diffusion of water

21. Osmosis in Cells

22. Active Transport: movement from an area of low concentration to areas of higher concentration (getting more crowded); requires energy
Exocytosis: when a vesicle fuses with the cell membrane to take material out
Endocytosis: brings material into the cell when a pocket in the membrane breaks off, forming a vesicle

23. Homeostasis & Cells

24. Cell Specialization
Cells in multicellular organisms are interdependent.
Cells in multicellular organisms are specialized to perform particular functions in the organism.

25. Cells – Tissues- Organs- Organ Systems- Organism

26. Cell
The basic unit of life.

27. Tissue A group of cells that perform a particular function.
Four types:
Connective
Epithelial
Muscle
Nervous

28. Organs
A group of tissues working together to perform a particular function.
Examples:
Heart
Stomach
Lungs

29. Organ System A group of organs working together. Examples:
Nervous system
Circulatory system
Digestive system

30. Organism
Any living thing.

31. A Good Review