1. Cells

2. Cell Theory All organisms are composed of one or more cells
Cells are the smallest units of life
All cells come from pre-existing cells

3. Functions of Life Metabolism – all chemical rxn occur in organism
Growth – grows in any amount
Reproduction – cells with offspring
Response – seek survival
Homeostasis – consistent internal environment, pH and temp
Nutrition – intake of energy

4. Order of Size in a Cell Organelles* Largest Bacteria Membrane Viruses
Molecules Smallest

5. How can we see these things?
Light Microscope
Electron Microscope

6. *Limiting Cell Size Surface area – intake of nutrients
Volume – energy, waste

7. *Cell Reproduction Maintain life Pass down genes Replace dead cells
Genes are segments of DNA on a chromosome

8. Types of Cells
Bacteria*
Animal*
Plant*

9. *Mitochondria vs. Chloroplasts
ATP formation
Double Membrane
Its own DNA
Ribosomes
Mitochondria has crista
Chloroplast has granum

10. Stem Cells
Stem cells are cells that retain the ability to divide and differentiate into various cell types.

14. *Prokaryotic Cells Cell wall Plasma membrane Flagella Pili Ribosomes
Nucleoid

15. *Eukaryotic Cells Larger and more complex than prokaryotic cells
Endoplasmic reticulum*
Ribosomes* Lysosomes
Golgi apparatus*
Mitochondria
Nucleus
Chloroplasts
Centrosomes
Vacuoles

16. *Magnification
A student observes a cell and draws it, using a high power lens of a light microscope. The diameter of the drawing is 10mm. The actual diameter of the cell is 10μm. What is the magnification of the drawing?
Magnification=size of image ÷ size of specimen

17. *Cell Division
The Cell Cycle
Mitosis

18. *The Cell Cycle Interphase Mitosis Cytokinesis G1 phase S phase
Prophase
Metaphase
Anaphase
Telophase
Cell division
Cytokinesis

19. *Tumour
Cells that multiply rapidly form a solid mass of cells is called a tumour.
Damage or error occur within the cell will cause this to happen

20. Interphase Longest phase in the cell cycle G1, S, G2
G1 is known as “Gap phase one” or “the growth phase one” where cell increases in mass with increase number of organelles
S phase is the “Synthesis phase” where main part of replication occurs, replication of chromosomes
G2 is known as “Gap phase two” or “growth phase two” where there is an increase in volume and mass in the form of increase of organelles are development of chromosomes and microtubules begin to form for preparation for mitosis

21. Mitosis Mitosis is also known as the “M phase”
There are four phases in mitosis
Prophase
Metaphase
Anaphase
Telophase
Tip: P-Mat is an easy way of memorizing this order

23. Prophase
The chromatin fibers become more tightly coiled to form chromosomes
The nuclear envelope disintegrates and nucloli disappears
The mitotic spindle begins to form and is complete at the end of prophase
The centromere of each chromosome has a region called the kinetochore that attaches to the spindle
The centrosomes move toward opposite poles of the cell due to lengthening microtubules

24. Metaphase
The chromosomes are moved to the middle or equator of the cell. Known as the metaphase plate
The chromosome’s centromeres lie on the plate
The movement of chromosomes is due to the action of the spindle which is made of microtubules
The centrosomes are now at the opposite poles

25. Anaphase
This is usually the shortest phase of mitosis. It begins when the two sister chromatids of each chromosome are split
These chromatids, now chromosomes, move toward the opposite poles of the cell
The chromatid movement is due to shortening of the microtubules of the spindle
Because the the centromeres are attached to the microtubules, they move towards the poles first
At the end of this phase , each pole of the cell has a complete, identical set of chromosomes

26. Telophase The chromosomes are at each pole
A nuclear membrane envelope begins to reform around each set of chromosomes
The chromosomes smart to enlongate to form chromatin
Nucleoli reappear
The spindle apparatus disappears
The cell is elongated and ready for cytokinesis

27. *Cytokinesis
Cytokinesis is not part of mitosis but follows after mitosis
Animal cells the cell involves an inward pinching of the plasma membrane to form cleavage furrow.
Plant cells the cell involves a cell plate
Results are two identical daughter cells that are identical to the parents (contains same number of chromosomes)

29. *Membranes
The structure of cell membranes are composed of proteins and lipids(phospholipids)
The outer cell membrane is called the plasma membrane due to the phospholipid bilayer member

30. Phospholipids Phospholipids are the back bone of the membrane
Phospholipid structure is compose of glycerol which is a three carbon compound with two of the carbons having a fatty acid tail and third contains an alcohol with a phosphate group attached to it
Fatty acids are non-polar therefore resists water. Hydrophobic
The alcohol phosphate group is water tolerant because it is polar. Hydrophilic

31. Cholesterol Only in animal
Cholesterol is located in the bilayer of the cell membrane, the hydrophobic region, where the fatty acids are located
These molecules role is membrane fluidity, which changes with temperature
Fluidity is the rate that objects can past through the membrane, higher the temperature the more easily things can past through

32. Proteins
There are two major types of proteins: integral protein and peripheral protein
Integral protein is hydrophobic and hydrophilic, the hydrophobic region hold the protein in place
Peripheral protein is only hydrophilic, therefore remains outside the membrane, these proteins are anchored to the member by integral protein

33. *

34. *

35. *Membrane Protein Function
Hormone binding sites
Enzymatic action
Cell adhesion
Cell-to-cell communication
Channels for passive transport
Pumps for active transport

36. Hormone binding sites
Proteins that expose their exterior in a particular way to fit perfectly with a hormone(binding) to relate a message to the interior of the cell.

37. Enzymatic Action
Cells have enzymes attached to membranes that catalyse many chemical reactions.
Often relates to the metabolic pathway

38. Cell Adhesion
Cell adhesion is provided by proteins when they hook together various ways to make connection.
Gap Junctions or Tight Junctions

39. Cell-to-cell Communication
Includes many molecules of carbohydrates
Provides an identification label representing cells of different species

40. Channels for passive transport
Provides a channel for substances to pass through the membrane from a high concentration to low centration

41. Pumps for active transport
Proteins shuttle a substance from one side of the membrane to the another by change shape
Requires energy

42. Passive Transport Passive transport does not require energy(ATP)
Passive transport occurs when there is an area of high concentration of a substance moves to an area of low centration.
The substance moves along what is called the concentration gradient.
Diffusion and Osmosis are examples of passive transport

43. Diffusion
Particles of any type move from a region of high concentration to a region of low concentration
Examples are oxygen diffusing into the cell while carbon dioxide diffuses out the cell

44. Osmosis
Osmosis involves only the passive movement of water molecule across a partially permeable membrane
A partially permeable membrane is one which only allows certain substances to pass through
Hyperosmotic concentration is the concentration of high solutes
Hypo-osmotic concentration is the concentration of low solutes
Concentration exchange ends when everything reaches equilibrium

45. Size and Charge
Substances that are small in size and non-polar move across membranes with ease. Gases like oxygen, carbon dioxide, and nitrogen fit in this category and water glycerol
Substances that are polar and/or large in size have difficulty passing through the membrane. Examples of these are chloride ions, potassium ions, sodium ions, glusose, and sucrose.

46. Active Transport Requires energy in the form of ATP
Active transport moves against the concentration gradient
Facilitated diffusion is an example of active transport

47. *Facilitated Diffusion
Facilitated diffusion is a particular type of diffusion involving a membrane with specific carrier proteins that are capable of combining with the substance to aid its movement.
The carrier protein changes shape to bind to the protein needed for transport.
Carrier protein requires energy to move against the concentration gradient

48. Sodium-Potassium Pump
A specific protein binds to three intracellular sodium ions
Binding of sodium ions causes phosphorylation by ATP
The phosphorylation causes the protein to change its shape, thus expelling sodium ions to the exterior
Two extracellular potassium ions bind to different regions of the protein and this causes the release of the phosphate group
Loss of the phosphate group restores the protein’s original shape thus causing the release of the potassium ions into the intracellular space

49. *Endocytosis
Endocytosis allows macromolecules to cross the cell membrane
Endocytosis occurs when a portion of the plasma membrane is pinch off to enclose macromolecules or particulates
The pinching of the membrane changes the shape of the membrane
The result of this is a formation of a vesicle

50. *Exocytosis
Exocytosis usually begins in the ribosomes of the rough ER and progresses through a series of four steps until the produced substance is secreted to the environment outside the cell.
Protein produced by the ribosomes of the rough ER enters the lumen of the ER
Protein exits the ER and enters the cis side or face of the Goli apparatus; a vesicle is involved
As the protein moves through the Goli apparatus, it is modified and exits on the trans face inside the vesicle
The vesicle with the modified protein inside moves to and fuses with the plasma membrane – this results in the secretion of the contents from the cell