1. 2.1 The Cell, as an Efficient, Open System
Cycling of Matter in Living Systems

2. Cells carry on all of the life processes including:
Intake of nutrients
Movement
Growth
Response to stimuli
Exchange of gases
Waste removal
Reproduction

3. Cell Membrane Protective barrier
Allows transport of materials into and out of the cell
Composed of double layer of lipid (fat) molecules and embedded proteins
Connects the cell to the external environment
Semi-permeable layer
Regulates the entry of molecules into and out of the cell

4. Nucleus Contains DNA, the genetic material of the cell
Directs cellular activities
Surrounded by the nuclear envelope, which has pores to allow the transport of materials

5. Cytoplasm Gel-like substance inside the cell membrane
Contains nutrients required by the cell to carry on the life process
Organelles are suspended in the cytoplasm
Allows for the movement of organelles and molecules within the cell, referred to as cytoplasmic streaming

6. Cell Wall – plants, bacteria and fungi
Rigid frame around the cell that provides strength and support.

7. Chlrorplasts - plants
Contain chlorophyll that produces a green color, they are the sites of photosynthesis
Photosynthesis uses energy from the sun to convert carbon dioxide and water into sugars for the plant’s use and storage
6H2O(l) + 6CO2(g)  C6H12O6(aq) + 6O2(g)

8. Vacuoles and Vesicles
Membrane bound structures that serve to store nutrients, products of secretion and fats
In plants, the central vacuole stores water for the cell
In plant cells, when fluids enter, the central vacuole swells, increasing the turgor pressure causing the cell to become rigid.
Vesicles transport substances through the cell.

9. Endoplasmic Reticulum
Series of interconnected small tubes that branch from the nuclear envelope.
Materials can be transported through these tubes
Rough endoplasmic reticulum has ribosomes attached to it and is associated with protein synthesis
Smooth endoplasmic reticulum is associated with fat and oil production

10. Ribosomes
May be attached to the endoplasmic reticulum or free in the cytoplasm
Sites where amino acids are assembled into proteins in the process of protein synthesis

11. Lysosomes Membrane bound sacs in the cell where digestion occurs
Defend against invading bacteria
Destroy damaged cell organelles
Control digestion of certain tissues during development

12. Golgi Apparatus Flat, disc shaped sacs involved in secretion
Receives substances from the endoplasmic reticulum and packages them for transport out of the cell

13. Mitochondria Rod-like structures
Convert chemical energy in sugars into energy the cell can use, cellular respiration
C6H12O6(aq) + 6O2(g)  6H2O(l) + 6CO2(g)

16. Chemical Composition of Cell Structures
Major elements making up the structure of plant and animal cells are carbon, hydrogen, oxygen and nitrogen
They are organized into four major organic compounds: lipids (fats and oils), carbohydrates (sugars, starches and cellulose), protein (muscle fibre) and nucleic acids (DNA).

17. Similarities: Plant and Animal
Both have cell membrane and an internal network of fibres, the cytoskeleton, made of lipids and proteins
Both have genetic material (DNA) made up of sugars, nitrogen bases and phosphate

18. Differences: Plant and Animal
Animal cells have centrioles, involved in cell division
Plant cells have cell walls
Plant cells contain chlorophyll, used for photosynthesis
Plant cells have a large central vacuole, animal cells have small vacuoles and vesicles

19. HOMEWORK:
BLM 6 & 7