1. Topic 5 The Energy of Life
Chemical Reactions
ATP
Enzymes
Passive Transport
Active Transport
Vesicular Transport

2. Energy Topic 5: Lesson 1 Resources Read Chapter 4.1 pp. 71-73
Lab-Rube Goldberg Diagram
Energy

3. Energy in Living Things
Energy – the ability to do work
Living things need energy to build and break molecules, move substances through the cell, to grow and develop, to move, etc.
Two Main Types of Energy
Potential
Kinetic
Energy of an object due to its position
Energy of motion

4. Examples of Energy in Biology
Potential
Kinetic
Chemical energy stored in covalent bonds of macromolecules (food)
Concentration gradient
Energy level of electrons in atom
Light – Sun
Sound – voice
Mechanical – movement of atoms and molecules, muscle contraction
Thermal – heat produced by living and nonliving things
Electrical – impulses produced in neurons

5. Electrons & Energy Levels
Electrons can absorb and release energy
Absorb energy when the move to a higher energy level
Release energy when the fall back down to a lower energy level - - - -
Nucleus

6. Electrons & Energy Levels- - - ++ ++
++++
Carbon
Oxygen
Electrons and their energy can be transferred to other molecules or atoms during a chemical reaction
If they move closer to a nucleus due to the transfer, they release energy

7. Energy & Covalent Bond
The energy released when a bond is broken is equal to the amount of energy that made the bond

8. Measuring Energy
calorie (cal) – amount of energy required to raise the temperature of 1 gram of water 1°C
Kilocalorie (kcal) = 1000 cal = 1 Calorie = 1 Cal

9. First Law of Thermodynamics
First Law of Thermodynamics/ Law of Conservation of Energy: energy cannot be created or destroyed although energy can be converted to other forms
The total amount of energy in the universe is constant
Heat energy is lost at each step
Heat energy is disordered and cannot be converted back to a useful form of energy

10. Second Law of Thermodynamics
Entropy, a measure of disorder, constantly increases in the universe
All energy transformations are not 100% efficient
The inefficiency is a result of the loss of heat after an energy transformation takes place
A constant input of free energy is required to keep up organization of a system

11. Second Law of Thermodynamics

12. Biochemical Reactions
Topic 5: Lesson 2
Resources
Read Chapter 4.2 pp
Chart – Biosynthesis & Decomposition
Worksheet – Contrasting Reactions
Biochemical Reactions

13. Metabolism Biosynthesis Decomposition Anabolic
Endergonic (input of energy)
Products are more organized than reactants
Ex: dehydration synthesis, photosynthesis, protein formation, disaccharide formation
Catabolic
Exergonic (release of energy)
Products are less organized than reactants
Ex: hydrolysis, cellular respiration, glycogen decomposition to glucose

14. ATP powers most cellular work
Sunlight energy
Photosynthesis in chloroplasts
Cellular respiration in mitochondria
Focus on the energy transformations
ATP
ATP powers most cellular work
Heat energy

15. Chemical Reactions Sustain Life
Chemical reactions may require energy input (endergonic) or release energy (exergonic).

16. RedOx Reactions

17. Electron Transport Chain (ETC)
ETC – a series of membrane proteins participating in sequential RedOx reactions
Contributes to oxidative phosphorylation

18. ATP Topic 5: Lesson 3 Resources Read Chapter 4.3 pp. 76-77
Worksheet – ATP & Cell Energy
Worksheet – Coupled Reactions
ATP

19. ATP Is the Cellular Energy Currency
Adenosine triphosphate (ATP) – temporarily “stores” and transfers the energy within cells

20. ATP  ADP + P

21. ATP  ADP + P

22. Mitochondria release energy from food, producing ATP from ADP.
ATP Can Be Reformed
Mitochondria release energy from food, producing ATP from ADP.

23. Coupled Reactions The energy from exergonic powers ATP formation
ATP is then used to power other endergonic reactions

24. Coupled Reactions

25. Phosphorylation

26. ATP = short-term energy “storage”
Typical human cell uses 2 billion ATPs/minute
You replace them just as quickly
Despite this, you can’t stockpile more ATP than that because ATP is an unstable molecule
For long-term energy storage, cells use fats/oils and glycogen/starch (animal/plant)

27. Enzymes Topic 5: Lesson 4 Resources Read Chapter 4.4 pp. 78-79
Worksheet – Enzyme Activity
Lab – Yeast (Sucrase) Lab
Mr. W’s Enzyme Song
Enzyme Function – University of Surrey
POGIL – Enzymes and Cellular Regulation
Enzymes

29. Enzymes
Catalyst  lowers the activation energy (EA) needed to start a chemical reaction; thus speeding up the rate of a reaction.
Enzymes
Proteins
Biological catalysts
Have ideal conditions
Are not used up during a reaction (can be used again and again)

30. Enzymes lower activation energy
Activation energy – the minimum amount of energy required for reactants to form products in a chemical reaction.

31. Enzymes Can Build or Breakdown Molecules

32. Enzyme-Substrate Binding
Lock & Key Model

33. Enzyme Specificity
Enzyme names describe what they do. For example, lactase speeds up the breakdown of lactose, a product found in milk products. This illustrates an important point…
Click cow for 1 min video clip
Most enzymes are SPECIFIC to one reaction! (meaning they can only catalyze a single reaction)

34. Enzyme-Substrate Binding- Induced Fit

35. Factors that affect enzymes
Increase reaction rate
Increasing amount of enzyme
Increasing amount of substrate
Increasing temperature to a certain point
Decrease reaction rate
Altering environmental conditions beyond ideal range (pH, temperature, salinity)
Inhibitors- can be competitive or non-competitive

36. Enzyme Denaturation
Environmental conditions affect the way proteins fold
If conditions aren’t ideal, the enzyme’s shape can change
Active site might not match substrate anymore
Enzyme can’t function
Enzyme has been denatured

37. Orthosteric Inhibitor
How Competition Affects Enzyme Activity
Substrate molecules typically bind to the active site of enzymes, but what if the active site changes shape or is blocked?
In many cases, the inhibitor is the product of the reaction that the enzyme catalyzes.
Allosteric Inhibitor
Orthosteric Inhibitor

38. Many Factors Affect Enzyme Activity
In a process called negative feedback, the product of a reaction slows the production of more product.

39. Many Factors Affect Enzyme Activity
In the opposite process, called positive feedback, the product of a reaction stimulates its own production.
Positive feedback
Enzyme 4’s product stimulates action of enzyme 1

40. Passive Transport Topic 5: Lesson 5 Resources
Read Chapter 4.5 pp
POGIL – Transport in Cells
Worksheet – Diffusion & Osmosis Practice
Matching – Osmosis
Passive Transport

41. Fluid Mosaic Model

42. Membrane as a Barrier

43. Traffic Across a Cell Membrane
The cell membrane is said to be selectively permeable – allows certain things to pass through but not others
Movement across the membrane is based on three criteria
Electric Charge
A charged molecule cannot cross the phospholipid bilayer
Size
Large molecules cannot cross the phospholipid bilayer
Polarity
Polar molecules do not easily cross the phospholipid bilayer

44. Can these molecules pass through the phospholipid bilayer?
N2 : nonpolar, small, no charge
C2H5OH (ethanol) : polar, small, no charge
H2O : polar, small, no charge
O2 : nonpolar, small, no charge
H+ : nonpolar, small, electric charge
Ca+2 : nonpolar, small, electric charge
Amino acid : nonpolar, large, uncharged
The direction the molecules move across the cell membrane is determined by the concentration gradient

45. “Gradient” Describes a Difference Between Neighboring Regions
Gradients have a tendency to dissipate.
If the spheres started bouncing around the box at random, they would become more evenly distributed over time.
High concentration of spheres
This arrow points down the concentration gradient since it starts at high concentration and ends at low concentration of spheres.
Low concentration of spheres

46. Concentration Gradients Have a Tendency to Dissipate
This is how it would look after time has passed. No energy is required to dissipate the gradient; it occurs by random motion.
Equal distribution of spheres
No concentration gradient

47. Concentration Gradients Have a Tendency to Dissipate
Maintaining this distribution of spheres within the box requires energy, since the concentration gradient has a tendency to dissipate.
High concentration of spheres
This arrow points down the concentration gradient since it starts at high concentration and ends at low concentration of spheres.
Low concentration of spheres

48. Passive Transport Does Not Require Energy
In passive transport, particles move from a high concentration to low concentration
“Down the concentration gradient”

49. Simple Diffusion

50. Key:
= ammonia
= O2

51. Key:
= ammonia
= O2

52. Equilibrium – Potential at which a particular molecule or ion passes easily in either direction across a cell membrane
Key:
= ammonia
= O2

53. Facilitated Diffusion
Molecules that cannot pass directly through the membrane need a type of protein channel
Transport protein channels are embedded in the cell membrane and help the movement of ions, small polar molecules, and some larger molecules into/out of the cell

54. Facilitated Diffusion of Large & Polar Molecules
The hydrophobic/nonpolar tails of the phospholipids repel hydrophilic/polar substances (ions, polar molecules)

55. Channel vs. Carrier Proteins

56. Channel vs. Carrier Proteins

57. Facilitated Diffusion of Ions
If there is a difference in ion concentration an electric charge will be produced

58. Osmosis Water polar, so it can not easily cross the cell membrane
Water will move from a high to a low concentration of water
Water uses aquaporins to cross the cell membrane

59. Aquaporins are used in Osmosis

60. Permeability of a membrane
Concentration gradients cause the movement of water towards the more concentrated solution
Solute can’t cross membrane, but water can

61. U-Shaped Tube Model

62. Example: A cell with 97% water, and 3% dissolved substances is placed in a 6% salt solution. Will water move in or out of the cell?
97% H2O
6% salt 94
___ % water

63. Tonicity
Tonicity refers to the relative amount of solutes in a solution surrounding a cell compared to the percentage of solutes inside a cell
Isotonic – solution and cell have equal concentration of solutes
Hypertonic – solution has a greater concentration of solutes compared to the cell’s cytoplasm
Hypotonic – solution has a lower concentration of solutes compared to the cell’s cytoplasm

64. Swells
Shrinks
Stays the same

65. 1 2 3 90 97 hypertonic crenate/shrink 100 98 hypotonic
swell /possibly lyse 96 96
isotonic
remain unchanged

66. Summary of Passive Transport

67. Osmosis in Animal Cells
Isotonic Solution
Hypotonic Solution/ LYSIS may occur
Hypertonic Solution/ CRENATION Occurs

68. Osmosis in Animal Cells

69. Osmosis in Plant Cells Isotonic Solution
Hypotonic Solution/ TURGOR PRESSURE Increases
Hypertonic Solution/ PLASMOLYSIS Occurs

70. Osmosis in Plant Cells

71. Active Transport Topic 5: Lesson 6 Resources Read Chapter 4.5B pp. 83
POGIL – Membrane Structure & Function
Practice Active vs. Passive Transport
Sodium-Potassium Pump
Summary of Active Transport
Symport & Antiport
Active Transport

72. Active Transport Requires ATP
Active transport moves molecules up or down the concentration gradient
The hydrolysis of ATP powers active transport

74. Sodium-Potassium Pump
Moves Na+ & K+ against their concentration gradients and help nerve cells and muscles function
3 Na+ binds to transport protein
Phosphate from ATP (energy) causes the protein to change shape delivering Na+ to the outside of the cell
2 K+ from the outside bind to protein
Phosphate group is released and the protein returns to its original shape
K+ is released inside

75. Sodium-Potassium Pump

76. Symport

77. Antiport

78. Vesicular Transport (Cytosis)
Topic 5: Lesson 7
Resources
Read Chapter 4.5C pp
Matching – Function of Cell Membranes
Lab – Cells & Movement of Materials
Worksheet – Reviewing the Concepts
Vesicular Transport Video
Vesicular Transport (Cytosis)

79. Vesicular Transport Requires ATP – a form of ACTIVE TRANSPORT
Requires that substances move across the cell membrane within a transport vesicle

80. Exocytosis

81. Endocytosis

82. Phagocytosis

83. Pinocytosis

84. Receptor-Mediated Endocytosis

85. The Life of a Protein

86. Membrane Transport Summary
Endocytosis (pinocytosis, phagocytosis, or receptor mediated)
Is the substance very large?
Is the substance entering or leaving the cell?
Entering
Yes No
Leaving
Exocytosis
Is the substance moving down its concentration gradient?
Active transport No
Yes
Is the substance nonpolar?
Facilitated diffusion No
Yes
Simple diffusion