1. Cell Structure & Function

2. Cell Theory Definition of Cell All living things are made up of cells.
Cells are the smallest working units of all living things.
All cells come from preexisting cells through cell division.
Definition of Cell
A cell is the smallest unit that is capable of performing life functions.

3. Prokaryotic Do not have structures surrounded by membranes
Few internal structures
One-celled organisms, Bacteria

4. Eukaryotic Plant Animal Contain organelles surrounded by membranes
Most living organisms
Plant
Animal

5. Parts of the Cell
Mitochondria
Vacules
Cytoplasm
Nucleus
Rough ER
Plasma membrane
Lysosomes
Smooth ER
Golgi Bodies
Ribosomes
All working together so that the cell can grow, work, repair, and reproduce

6. Surrounding the Cell Plasma Membrane
Outer membrane of cell that controls movement in and out of the cell
Double layer

7. Functions of Plasma Membrane
The Plasma Membrane
4/26/2017
Functions of Plasma Membrane
Protective barrier
Regulate transport in & out of cell
Allow cell recognition
Receptor proteins function in cell communication
Contains the cytoplasm (fluid in cell)
Provide a binding site for enzymes
G. Podgorski, Biol. 1010

8. Homeostasis
Cells must keep the proper concentration of nutrients and water and eliminate wastes.
The plasma membrane is selectively permeable – it will allow some things to pass through, while blocking other things.

9. Structure of the Plasma Membrane
Lipid bilayer – two sheets of phospholipids.
Found around the cell, the nucleus, vacuoles, mitochondria, and chloroplasts.
Embedded with proteins and strengthened with cholesterol molecules.

10. What is a Phospholipid?
It’s a pair of fatty acid chains and a phosphate group attached to a glycerol backbone.
Polar (hydrophilic) phosphate heads face out & the nonpolar (hydrophobic) fatty acids hang inside.

11. Membrane Proteins
Determine what particles can pass through the membrane.
Serve as enzymes (may speed reactions).
Act as markers that are recognized by chemicals and molecules from the inside and the outside of the cell (the immune system).

12. Receptors, enzymes, crossing
Phosphate
Polar
Cholesterol
structure & support
Fatty acid
nonpolar
Carbohydrate chains
identification
Membrane proteins
Receptors, enzymes, crossing
FLUID- because individual phospholipids and proteins can move around freely within the layer, like it’s a liquid.
MOSAIC- because of the pattern produced by the scattered protein molecules when the membrane is viewed from above.
Extracellular
(outside the cell)
Intracellular
(inside the cell)

13. Nucleus Directs cell activities Contains genetic material - DNA
Separated from cytoplasm by nuclear membrane
Surrounds nucleus
Made of two layers
Openings allow material to enter and leave nucleus

14. Inside the nucleus Chromosomes Nucleolus Made of DNA
Contain instructions for traits & characteristics
Nucleolus
Contains RNA to build proteins

15. Endoplasmic Reticulum
Moves materials around cell
Smooth type: cholesterol & fat synthesis & breakdown (lipid metabolism); lacks ribosomes
Rough type: the cell’s membrane factory; ribosomes embedded in surface

16. Ribosomes Make proteins Each cell contains thousands
Found on ribosomes & floating throughout the cell

17. Mitochondria Produces energy
Cellular respiration - chemical reactions breaking down fats & carbohydrates
Controls level of water and other materials in cell
Recycles and decomposes proteins, fats, and carbohydrates

18. Golgi Bodies Protein packaging
Proof reads proteins & makes minor corrections
Move materials within the cell
Move materials out of the cell

19. Lysosomes Breaks down molecules
‘Digests’proteins, fats, and carbohydrates
Transports undigested material to cell membrane for removal
Cell breaks down if lysosome explodes
Hydrolytic
enzymes

20. Vacuoles sacs for storage Also used for digestion, and waste removal
Contains water solution
Help plants maintain shape

21. Cytoplasm Fills cell & holds organelles
Gel-like mixture - mostly water
Protects & stabilizes organelles
Surrounded by cell membrane

23. Cellular Respiration
Cells break down food sources i.e. glucose, fats, and protein &release their stored energy.
Produce energy storage molecules called ATP – adenosine triphosphate.

24. Anaerobic Processes No oxygen is required for these processes.
Includes glycolysis, the breakdown of glucose, and fermentation.
Some bacteria and yeast are examples of anaerobes.

25. Glycolysis Occurs in the cytoplasm. Breaks down glucose
2 molecules of pyruvate (3- carbon structures)
2 ATP molecules are formed.
2 NADH energy shuttles are also formed.

26. Fermentation
Pyruvate can be metabolized by: Alcoholic fermentation or Lactic acid fermentation
Alcoholic Fermentation produces ethyl alcohol and CO2
Lactic acid fermentation produces lactic acid.

27. Aerobic Processes C6H12O6 + 6O2  6CO2 + 6H2O + Energy
Requires oxygen.
Most organisms are aerobes.
Equation for Aerobic respiration:
C6H12O6 + 6O2  6CO H2O + Energy

28. The Mitochondria
If O2 is present following glycolysis, pyruvate is modified and enters the mitochondria.
Here food is broken down completely into CO2.
Energy storage molecules like NADH and ATP are produced.

29. The Role of Oxygen Energy carriers like NADH drop off electrons
ATP
Energy from electrons O2
Energy carriers like NADH drop off electrons
As the electrons “fall” to oxygen energy is stored in a payload of ATP.
Oxygen picks up electrons and hydrogen ions to form water.
H2O

30. ATP: Adenosine Triphosphate
ATP is the cells energy currency.
Cellular work such as metabolism, transport, and movement is powered by the breakdown of ATP.
ATP Structure
Ribose – a 5-carbon sugar
Adenine – a N-base
3 phosphate groups

31. ATP / ADP Cycle ATP is constantly being used and remade in the cell.
Energy is released or stored by breaking or making a phosphate bond.

32. Summary of Cellular Respiration
Process
Where Process Occurs
Net Gain of ATP
Per Glucose
Anaerobic Glycolysis & Fermentation
Cytoplasm
2 ATP
Aerobic Krebs Cycle and Electron Transport
Mitochondrion
36 ATP

34. Selectively Permeable
Phospholipid
Bilayer
Active & Passive transport mechanisms
move molecules across the membrane

35. Transport Across the Membrane
Passive
Active

36. Simple Diffusion Requires NO energy
Molecules move from area of HIGH to LOW concentration
The solute moves down the concentration gradient – from an area of high concentration of solute to an area of low concentration of solute until equilibrium is reached then simple diffusion stops

37. Simple Diffusion
Diffusion is a PASSIVE process which means no energy is used to make the molecules move, they have a natural KINETIC ENERGY
Example: Oxygen or water diffusing into a cell and carbon dioxide diffusing out.

38. Facilitated Diffusion
Molecules will randomly move through the pores in Transport Proteins.
Uses transport proteins to move high to low concentration
Examples: Glucose or amino acids moving from blood into a cell.
High concentration of solute  Low concentration of solute

39. Facilitated Diffusion
Some Carrier proteins do not extend through the membrane.
They bond and drag molecules through the lipid bilayer and release them on the opposite side.

40. Facilitated Diffusion
Other carrier proteins change shape to move materials across the cell membrane
Along the concentration gradient

41. Osmosis Diffusion of water across a membrane
High water potential
Diffusion of water across a membrane
Moves from HIGH water potential (low solute) to LOW water potential (high solute)
Low water potential

42. Cells in Solutions

43. NO NET MOVEMENT OF H2O (equal amounts entering & leaving)
Isotonic Solution
Hypotonic Solution
Hypertonic Solution
NO NET MOVEMENT OF H2O (equal amounts entering & leaving)
CYTOLYSIS
PLASMOLYSIS

44. Active Transport Requires energy or ATP
Moves materials from LOW to HIGH concentration
Examples: Pumping Na+ (sodium ions) out and K+ (potassium ions) in against strong concentration gradients. The sodium potassium pump important in nerve impulses
AGAINST concentration gradient

45. Exocytosis- moving things out.
Molecules are moved out of the cell by vesicles that fuse with the plasma membrane.
Active Transport
This is how many hormones are secreted.

46. Endocytosis- moving things in
Pinocytosis
Phagocytosis
Most common form of endocytosis.
Ingestion of solid particles by endocytosis
Takes in molecules dissolved in H2O.
Fuses with lysosomes and the material is degraded