1. Chapter 3 (and some of 4): Cells and Cellular Metabolism
Part 1: Overview of Cells, Cell Membrane

2. Human cells Basic unit of structure & function
200 different cell types
Made of C, O, H, N + trace elements
3 main parts:
Plasma membrane
Cytoplasm
Nucleus

3. Cell diversity

4. cell structure

5. Plasma membrane
Function: enclose cell contents, control exchange of substances with environment, cell communication
Made of:
Lipid bilayer
Cholesterol
Glycolipids
Proteins

6. Fluid mosaic model
Proteins float in fluid lipid bilayer

7. Membrane lipids: Phospholipid: Polar/hydrophilic (water-loving) “head”
Nonpolar/hydrophobic (water-fearing) “tail”

8. Lipid bilayer

9. Membrane lipids Cholesterol 20% of membrane lipid Stabilize membrane
Maintain fluidity

10. Membrane lipids Glycolipids glycolipid Lipid + sugar attached
For cell recognition
glycolipid

11. Membrane proteins integral proteins Integral Proteins
Inserted into lipid bilayer
Have both hydrophilic & hydrophobic regions
Functions: enzymes, transport, receptors (relay messages)
integral proteins

12. Membrane proteins peripheral protein Peripheral Proteins
Attached loosely to membrane
Functions: support, enzymes, movement, linkage
peripheral protein

13. glycoprotein glycoprotein protein + sugar attached
Serves as specific biological marker  cell recognition
glycoprotein

14. Membrane protein functions
Transport
Receive chemical messages
Maintain cell
shape

15. Membrane protein functions
Enzyme activity
Intercellular
joining
Cell-cell
recognition
“ID tags”

16. Warm-Up
Name the three basic parts of a cell and describe the functions of each.
Why do phospholipids organize into a bilayer – tail-to-tail – in a watery environment?

17. Hypertonic, isotonic, or hypotonic?
Warm-Up
Hypertonic, isotonic, or hypotonic?
What type of fluid might be infused into the bloodstream of a patient who needs fluid drawn out from swollen tissues?
What type of fluid might be used (carefully) to rehydrate the tissues of extremely dehydrated patients?
In a U-tube separated by a selectively permeable membrane, there is .2 M glucose in Side A, and .4 M glucose in Side B. Side A is ____ compared to Side B, and Side B is ____ compared to Side A.
If the membrane in #3 is only permeable to water, what will happen?

18. Part 2: Membrane Transport
Chapter 3: Cells
Part 2: Membrane Transport

19. Membrane transport Interstitial fluid: Fluid outside cells
Rich, nutritious “soup” – amino acids, sugars, fatty acids, vitamins, hormones, salts, wastes
Selective Permeability:
Plasma membrane only allows some substances to enter cell
Nutrients in, wastes out
By passive or active transport

20. Passive transport No energy (ATP) needed
Molecules move down concentration gradient from HIGH  LOW concentration
Types: diffusion, filtration

21. Simple diffusion
Nonpolar & lipid-soluble substances diffuse directly through lipid bilayer
Eg. O2, CO2, fat-soluble vitamins

22. Facilitated diffusion
Transport proteins (carrier or channel proteins) assist molecules across membrane
Eg. glucose, amino acids, H2O, ions

23. Channel proteins
Water-filled channels
Eg. ions

24. Carrier proteins
Binds to molecule, changes shape, ferries it across membrane
Eg. glucose transporter

25. osmosis
Diffusion of H2O
Aquaporins: channel proteins for H2O passage

28. Tonicity
Ability of solution to change shape or tone of cells by changing water volume
Isotonic = equal concentration solutes
Hypertonic = higher conc. of solutes
Hypotonic = lower conc. of solutes

29. Effect of solutions on red blood cells

30. RBC’s in isotonic & hypertonic solutions

31. Active transport Energy (ATP) is needed!!
Move molecules against concentration gradient from LOW  HIGH concentration
Types: Primary and Secondary

32. Primary Active Transport
Directly uses ATP to drive transport
Eg. Ca2+ pump, H+ pump, Na+-K+ pump

33. Sodium-Potassium Pump

34. Secondary active transport
Move more than 1 substance at a time
Symport: 2 substances moved in same direction
Antiport: 2 substances cross in opposite directions
Eg. Co-transport of sugars, amino acids, ions

35. Secondary active transport: Na+/Glucose Cotransport

36. Vesicular transport
Fluid & large particles transported across membranes in vesicles (sacs)
Exocytosis: “out of cell” – eject substances
Endocytosis: “within the cell”- ingest substances

37. Types of endocytosis
Phagocytosis: (cell eating) – engulf large or solid material
eg. WBC engulf bacteria

38. Types of endocytosis
Pinocytosis: (cell drinking) – fluid w/dissolved molecules
Eg. intestinal cells

39. Types of endocytosis
Receptor-mediated endocytosis: concentrate specific substances (ligands) that bind to receptor proteins
Eg. insulin, iron, cholesterol

40. Part 3: Cytoplasm & Nucleus
Chapter 3: Cells
Part 3: Cytoplasm & Nucleus

41. Cytoplasm Between plasma membrane & nucleus Three elements:
Cytosol: fluid
Eg. water, proteins, salts, sugars
Organelles: specific functions
Inclusions: chemical substances that vary depending on cell type
Eg. glycogen (liver), lipid droplets (fat cells), melanin (skin & hair)

42. organelles “little organs”
Specialized compartments  specific functions
Membranous = membrane- bound
Mitochondria, peroxisomes, lysosomes, ER, Golgi apparatus
Non-membranous = no membrane
cytoskeleton, centrioles, ribosomes

43. Endomembrane system System of organelles that work to
Produce, store, export biological molecules
Degrade harmful substances
Nuclear envelope, rough ER, smooth ER, Golgi apparatus, secretory vesicles, lysosomes

44. Nucleus Control center  contains DNA Most cells have only 1 nucleus
Multinucleate: many nuclei (muscle, some liver cells)
Anucleate: no nucleus (mature RBC)
Three main structures:
Nuclear envelope
Nucleoli
Chromatin

45. Multinucleated Muscle Cells
Anucleated Red Blood Cells
Multinucleated Liver Cells

46. Nuclear envelope Double membrane barrier surrounds nucleus
Outer part continuous with Rough ER
Nuclear pores: control entry/exit of molecules

47. Nucleolus (nucleoli) Dark-staining bodies in nucleus 1-2 per cell
Site where ribosomes are made

48. chromatin Chromatin = DNA + Proteins
Nucleosome = DNA wrapped around 8 histone proteins
Histones allow for compact and orderly packing of long DNA molecules

50. During cell division, chromatin condenses to form chromosomes.

51. replication
Make identical copies of DNA before a cell divides

52. Mitosis Part of cell division
Replicated DNA divided into 2 daughter cells
Usually lasts about an hour
Interphase  prophase  metaphase  anaphase  telophase & cytokinesis

54. Cell Cycle
Why must cells divide?
Growth
Repair
Maintenance

55. Cell Differentiation
Process in which cells develop different characteristics and functions. How does this occur?
Some DNA is expressed and some is repressed
By birth, humans have over 200 types of specialized cells

56. Cell Death Apoptosis Normal part of development
gets rid of webbing, removes extra brain cells, follows a sunburn

58. Cancer Results from changes in the cell cycle Hyperplasia
uncontrolled cell division
Dedifferentiation
lose the specialized functions
Invasiveness
break through boundaries

59. Cancer
Angiogenesis
cells induce the formation of blood vessels enabling the cancer to persist, grow and spread
Metastasis
tendency to spread into other tissues

60. Figure 12.17 The growth and metastasis of a malignant breast tumor

61. Figure 12-17x1 Breast cancer cell

62. Figure 12-17x2 Mammogram: normal (left) and cancerous (right)

63. DNA = blueprint for protein synthesis
Gene: segment of DNA that codes for 1 polypeptide
Exon: part of DNA that codes for polypeptides
Intron: part of DNA that is noncoding (not “junk”!)

64. Information Flow: DNA  RNA  proteins

65. Protein synthesis Transcription: RNA formed from DNA Occurs in nucleus
Types: mRNA, tRNA, rRNA
Translation: protein synthesis
polypeptide formed from mRNA
Occurs in cytoplasm
By ribosomes

66. Extracellular materials
Any substances outside cells
Body fluids (blood plasma, interstitial fluid)
Cellular secretions (saliva, mucus, gastric fluids)
Extracellular matrix (ECM): “glue” that holds cells together; jelly-like substance made of proteins (like collagen) and carbs

67. Metabolic Reactions Anabolism Catabolism breaking down macromolecules
building macromolecules
requires energy
Catabolism
breaking down macromolecules
releases energy

69. Provides biochemicals for cell growth and repair Dehydration synthesis
Anabolic Reactions
Provides biochemicals for cell growth and repair
Dehydration synthesis
joins monosaccharides
joins glycerol and fatty acids
joins amino acids
with each bond a water molecule is released

73. Anabolic Steroids Lipids that stimulate anabolism
Used to treat disease
Used to increase muscle mass
damage liver
increase risk of heart disease
change in hormones
infertility
psychological disorders

74. Catabolic Reactions Hydrolysis reactions
decomposes lipids, carbohydrates and proteins using a water molecule to break the bonds
Occurs during digestion

75. Control of Metabolic Reactions
Enzymes
protein catalysts
lowers the activation energy needed to begin a metabolic reaction
not consumed during the reaction
Why is it crucial that the body utilizes enzymes during metabolism?

76. Enzymes Works similar to a lock and key Induced fit model
substrate: substance that an enzyme acts upon
active site: part of the enzyme that temporarily joins with the substrate
Works similar to a lock and key
catalase and hydrogen peroxide
lactase and lactose

77. Factors that Alter Enzymes
Denaturation
High heat
Radiation
Electricity
Chemicals
Extreme changes in pH

78. Energy for Metabolic Reactions
capacity to change or move matter
Release of chemical energy
cells “burn” glucose molecules by oxidation
cellular respiration

79. Cellular (Aerobic) Respiration
Breakdown of molecules in the presence of oxygen
Glycolysis
Kreb’s Cycle
Electron Transport
Chain
End result of 38 ATP

80. Anaerobic Respiration
Breakdown of molecules when oxygen is not present
Lactic Acid fermentation
Human muscle cells
Soreness after exercising
Only results in 2 ATP