Cell Structure & Function

1. Cell Structure & Function

2. Describe this picture. What is the basic substance required to make this structure.?

3. BRICKS ACT AS BUILDING BLOCKS TO CREAT THE BRICK BUILDING.

4. What are we made up of?

6. So what is the definition of a cell??

7. They are building blocks of all living things and they are the basic unit of life !!!!!

8. What do you think the ‘building block of a dog is ?

9. So what are the various points you can think of to describe a cell?

10. Cell Theory • All living things are made up of cells. • Cells are the smallest working units of all living things. • They are the structural and functional unit of life. (why?) • All cells come from preexisting cells through cell division.

11. Refined Definition of Cell A cell is the smallest structural and functional unit of life.

12. Cell Theory • All living things are made up of cells. • Cells are the smallest working units of all living things. • They are the structural and functional unit of life. (why?) • All cells come from preexisting cells through cell division.

13. Definition of Cell A cell is the smallest structural and functional unit of life.

14. Examples of Cells Amoeba Plant Stem Bacteria Red Blood Cell Nerve Cell

15. tallest trees adult human chicken egg frog embryo most eukaryotic cells mitochondrion most bacteria virus proteins diameter of DNA double helix atoms

16. “Typical” Plant Cell http://waynesword.palomar.edu/images/plant3.gif

17. “Typical” Animal Cell http://web.jjay.cuny.edu/~acarpi/NSC/images/cell.gif

18. Cell Parts Organelles

19. Surrounding the Cell

20. Cell Membrane • It is the Outer membrane of an animal cell. It is located below the cell wall in the plant cell. • Its main function is to control the movement of substances in and out of the cell. • It is a Double layer called lipid bi layer • Scientists say that the cell membrane is selectively permeable, which means that only certain substances can permeate (go through) the membrane. • It is found in both plant and animal cells • It also helps give shape to the cell http://library.thinkquest.org/12413/structures.html

21. Cell membrane

22. Cell Wall • Most commonly found in plant cells & bacteria. NOT present in animal cells • Surrounds the cell membrane in a plant cell • Most important function is to give the cells shape and rigidity. • It also Supports & protects cells. http://library.thinkquest.org/12413/structures.html

23. Inside the Cell

24. Cytoplasm • Jelly-like substance • Surrounded by cell membrane • All cell organelles are embedded in this. • It contains the chemicals which are necessary to carry out all the reactions that happen within a cell. • Important chemical reactions occur in the cytoplasm whereby some of the products are utilized by the organelles.

25. Nucleus • Easiest organelle to see under the microscope • Control center of the cell • Directs cell activities • Separated from cytoplasm by nuclear membrane • Contains genetic material – DNA • Controls the production of proteins in the cells • All the information regarding the cell and its activities are stored here.

26. Nucleus

27. Chloroplast • Usually found in plant cells. Also present in trace amounts in Bacteria, fungi and algae. • It is not present in animal cells. • Surrounded by two membranes (inner and outer) • Contains a green pigment called chlorophyll which traps light energy and converts it into food through photosynthesis. • It contains its own DNA. http://library.thinkquest.org/12413/structures.html

28. Chloroplast

29. Mitochondria • Produces energy through chemical reactions – breaking down food. • Surrounded by two membranes (outer and inner membrane). The inner membrane is folded several times. • Controls level of water and other materials in cell • Recycles and decomposes proteins, fats, and carbohydrates • Contain their own DNA. http://library.thinkquest.org/12413/structures.html

31. Vacuoles • Membrane-bound sacs for storage, digestion, and waste removal •  Vacuoles may contain large food particles, enzymes, water, or many other substances.  • Usually one large vacuole is present in plant cell (takes up 95% of space) • Animal cells have small vacuoles but they are more in number. http://library.thinkquest.org/12413/structures.html

33. Ribosomes • Each cell contains thousands of ribosomes. • Produced in the nucleus of a cell • They act as factories of the cell to produce Proteins. • They can be found either in their free form in the cytoplasm or attached to an organelle (The rough Endoplasmic Reticulum.) • It is made up of a large sub unit and a small sub unit. http://library.thinkquest.org/12413/structures.html

35. Lysosome • Digestive organelle. • They contain acid enzymes to break down food particles,waste materials and cellular debris. It can also destroy organelles that have been damaged. If the celllacks an adequate amount of food, the lysosomes may actually digest healthy organelles to provide the cell with energy. • Found only animal cells • Should the lysosome break and release its powerfulenzymes, the entire cell can be destroyed, which is why the lysosome is sometimes called the "suicide sac."

37. Endoplasmic Reticulum • Two types – Smooth and rough ER • Rough ER – as they have ribosomes attached to their surface. Protein synthesis occurs here. • Smooth ER – Carbohydrate metabolism and lipid and steroid synthesis. No ribosome present. • Extends from the Nucleus