1. Chapter 4
Metabolism
Anatomy & Physiology
ivyanatomy.com

2. Cellular Metabolism Metabolism is the sum of all reactions in the body
Anabolism
Catabolism
Synthesize larger molecules from smaller ones.
Cells use energy
Decomposes larger molecules into smaller ones.
Releases energy for cellular use

3. Anabolic Reactions Dehydration Synthesis
A water molecule is released to join molecules together.
Most polymers are synthesized through dehydration synthesis.
H2O + +
Glucose molecules are joined by dehydration synthesis

4. Dehydration Synthesis
Dehydration synthesis synthesizes polysaccharides, fats, proteins, and nucleic acids from their monomers.
Several Monomers
Polymer
H2O +

5. Dehydration Synthesis
Dehydration synthesis of a polysaccharide.
H2O +
glucose
Amylose is a polysaccharide composed of several thousand glucose monosaccharides.

6. Dehydration Synthesis
Dehydration synthesis of a triglyceride. +
1 glycerol fatty acid molecules
triglyceride
H2O

7. Dehydration Synthesis
Dehydration synthesis of a polypeptide.
amino acid amino acid
dipeptide +
H2O

8. Dehydration Synthesis
Dehydration synthesis of a polynucleotide. P O OH P O OH
CH2
CH2 S B S B S
CH2 B P O OH S
CH2 B P O OH OH +
H2O

9. Hydrolysis
Water is consumed to break apart the molecules hydrolysis is the reverse of dehydration synthesis hydrolysis releases energy from chemical bonds
H2O + +

10. Hydrolysis
Hydrolysis is used to decompose polysaccharides, fats, proteins, and nucleic acids into their monomers.
Polymer
Several Monomers +
H2O

11. Hydrolysis + H2O Hydrolysis of a polysaccharide.
glucose
Water is added to amylose, which decomposes into glucose molecules

12. Hydrolysis
Hydrolysis of a triglyceride (fat). +
H2O +

13. Hydrolysis + + H2O Hydrolysis of a dipeptide. amino acid + amino acid

14. Hydrolysis + S S S S B H2O B B B Hydrolysis of a dinucleotide.P O OH
CH2 S B
Nucleotide Nucleotide S
CH2 B P O OH S
CH2 B P O OH S
CH2 B P O OH
H2O +

15. Dehydration Synthesis+
Monomers linked by covalent bond
Hydrolysis +
Monomers linked by covalent bond

16. Activation energy
Activation Energy – Amount of energy required to initiate a reaction

17. Activation energy
A catalyst – increases the rate of the reaction without being consumed by the reaction
Activation energy without catalyst
Activation energy with a catalyst
Catalysts lower the activation energy required to initiate a reaction
Lower energy state

18. Enzymes Characteristics of enzymes
Enzymes lower the activation energy of a reaction
Most enzymes are proteins
Enzymes catalyze reactions (they increase the rate of reactions, but are not consumed by the reaction)
Enzymes are specific to one substrate*.
Most enzymes end in ____ase. (lipase, protease, nuclease, ATPase, etc.)
*A substrate is the target molecule of an enzyme

19. Proteins
Enzymes catalyze reactions (increases rate), but are not consumed by the reaction (reusable).
Substrates
Product A B A B A B A B
Active Site
Active Site
Active Site
Active Site
Enzyme
Enzyme-Substrate Complex
Enzyme is unchanged
Synthesis reaction involving an enzyme

20. Enzymes The rate of an enzyme-catalyzed reaction is limited by:
1. The concentration of substrate
2. The concentration of enzyme
3. Enzyme efficiency
Measures how efficiently the enzyme converts substrates into produces

21. Metabolic Pathways
A metabolic pathway is a complex series of reactions leading to a product
Metabolic Pathways are controlled by several enzymes

22. Metabolic Pathways Enzyme A = Rate-limiting Enzyme
The product of each reaction becomes the substrate of next reaction.
Each step requires its own enzyme
The least efficient enzyme is the “Rate-Limiting Enzyme”
Rate-limiting enzyme is usually first in sequence
Substrate 1 2
Enzyme B
Enzyme A 3
Enzyme C 4
Enzyme D
Product
Enzyme A = Rate-limiting Enzyme

23. Negative Feedback in Metabolic Pathway
In some pathways the product inhibits the enzymes through negative feedback inhibition.
Negative feedback regulates the amount of product being produced.
Substrate 1 2
Enzyme B
Enzyme A 3
Enzyme C 4
Enzyme D
Product
Rate-limiting

24. Enzymes Cofactor substance that increases the efficiency of an enzyme
Cofactors include ions (zinc, iron, copper) and coenzymes
Coenzymes are organic cofactors
Coenzymes include Vitamins (Vitamin A, B, D)
Reusable – required in small amounts

25. Enzymes
Vitamins are essential organic molecules that humans cannot synthesize,
so they must come from diet
Many vitamins are coenzymes
Vitamins can function repeatedly, so can be used in small amounts.
Example: Coenzyme A

26. Energy
Energy: is the capacity to change something, or ability to do work.
Common forms of energy:
Heat
Radiant (light)
Sound
Chemical
Mechanical
Electrical

27. Energy Conservation of Energy:
Energy can be converted from one form to another, but it cannot be created or destroyed.

28. Energy Examples of transferring energy:
Automobile energy converts chemical energy into mechanical and heat energy
Lightbulb converts electrical energy into radiant (light) energy and heat energy
Tree converts radiant (light) energy from the sun into chemical energy.

29. ATP Molecules ATP P ATP (Adenosine Triphosphate)
carries energy in a form the cell can use
currency of energy in a cell.
adenine
ribose P
Adenosine
Triphosphate
ATP

30. Hydrolysis of ATP
Cells obtain energy by hydrolyzing the third phosphate of ATP, releasing energy stored in the chemical bond.

31. ATP
Cells have a limited supply of ATP, so they must continually regenerate ATP supplies through cell respiration.
ATP is similar to cash. Cells have a limited supply and when it’s gone, it’s gone.

32. ATP = Energy currency for cells
Cellular Respiration
Cell Respiration: transfers the energy from food molecules into a form the cells can use (ATP).
Energy from foods such as glucose is used to make ATP for the cell.
36 – 38 ATPs
Initial fuel or energy source
ATP = Energy currency for cells
Reaction depicting the aerobic respiration of 1 glucose molecule into energy for 36 – 38 ATPs

34. Cell respiration replenishes ATP supplies.
Energy invested
from respiration
Cell respiration replenishes ATP supplies. +
Energy released
for metabolism
Normal cell activities deplete ATP supplies.

35. Overview of Cell Respiration
Oxidation – transfer of electrons to a final electron acceptor, such as oxygen.
Oxidation releases energy from glucose + +
Glucose (C6H12O6)
6 O2
6 CO2
6 H2O + +

36. Release of Chemical Energy
Oxidation of glucose releases energy that is use to produce new ATP
C6H12O6
(Glucose)
6 CO2 +
6 O2
6 H2O
Energy + +
Energy is transferred to ATP:
40% is captured to produce ATP
60% is released as heat

37. Overview of Cell Respiration
oxygen present (aerobic respiration)
2. Citric Acid Cycle
3. Electron Transport Chain
1. Glycolysis
Glucose (C6H12O6)
Lactic Acid
oxygen not present (anaerobic respiration)

38. Electron Carriers (NADH & FADH2) + + + + NAD+ NAD 2 FAD 2 FAD + H H H
(each hydrogen has an electron) H -e H
-e -e H +
NAD+ +
NAD + 2 H -e H2
-e -e +
FAD + 2
FAD

39. Electron Carriers (NADH & FADH2) Electron Transport Chain
NADH is worth 3 ATP
FADH2 is worth 2 ATP
To extract ATP from NADH and FADH2, the electron carriers must first be transferred to the ETC

40. Glycolysis Occurs in cytosol Anaerobic (no oxygen required)
Yields 2 ATP per glucose

41. Glycolysis 1. Phosphorylation 2. Cleavage 3. Oxidation (next slide)
ATP
Glucose (C6H12O6)
ATP
1. Phosphorylation
ADP
ADP C P
2. Cleavage C P C P
2ADP
2ADP
2 ATP
2ATP
NAD+
NAD+
NADH
NADH
3. Oxidation
(next slide) C C
pyruvate
pyruvate

42. Glycolysis 1. Phosphorylation 2. Cleavage 3. Oxidation No Oxygen
ATP
ATP
1. Phosphorylation
ADP
ADP C P
2. Cleavage C P C P
2ADP
2ADP
2 ATP
2ATP
NAD+
NAD+
NADH
NADH
3. Oxidation C C
pyruvate
pyruvate
No Oxygen
Oxygen Available
Lactic Acid
anaerobic respiration
aerobic respiration
2. CAC
3. ETC

43. Anaerobic RespirationH
-e -e H
-e -e C
NAD+ + C
NAD
Pyruvate
Lactic Acid

44. Anaerobic Respiration
Oxygen debt is the amount of O2 required to convert the lactic acid back to glucose after exercise. O
oxygen H
-e -e C C
Lactic Acid
Glucose (C6H12O6)

45. Electron Transport Chain
Citric Acid Cycle
&
Electron Transport Chain

46. Glycolysis 1. Phosphorylation 2. Cleavage 3. Oxidation pyruvate
ATP
Glucose (C6H12O6)
ATP
1. Phosphorylation
ADP
ADP C P
2. Cleavage C P C P
2ADP
2ADP
2 ATP
2ATP
NAD+
NAD+
NADH
NADH
3. Oxidation C C
pyruvate
pyruvate

47. Glycolysis 1. Phosphorylation 2. Cleavage 3. Oxidation No Oxygen
ATP
ATP
1. Phosphorylation
ADP
ADP C P
2. Cleavage C P C P
2ADP
2ADP
2 ATP
2ATP
NAD+
NAD+
NADH
NADH
3. Oxidation C C
pyruvate
pyruvate
No Oxygen
Oxygen Available
Lactic Acid
anaerobic respiration
aerobic respiration
2. CAC
3. ETC

48. mitochondria Mitochondria are the powerhouse of cell.
Most ATP are synthesized within mitochondria

49. Priming Pyruvic Acid for the Citric Acid Cycle
Before pyruvic acid can enter the CAC it must first be converted into acetyl CoA C
pyruvate
1 molecule of CO2 is released
NAD+
NADH
For each pyruvic acid, this reaction produces
1 CO2 molecule
1 NADH molecule
1 Acetyl CoA C
acetic acid
Coenzyme A
Acetyl CoA is the substrate for the citric acid cycle. C
acetyl CoA

50. Citric Acid Cycle
The citric acid cycle occurs in the matrix of the mitochondrion.

51. + Citric Acid Cycle acetyl CoA Co-Enzyme A is released
oxaloacetic acid C C C
citric acid
3 NAD+
Citric Acid Cycle
3 NADH C C
FADH2
2CO2
FAD
ATP
ADP + P

52. Products of the citric acid cycle:
1 ATP
3 NADH
1 FADH2
2 CO2

53. Each Glucose = 2 turns of the CAC
pyruvate
pyruvate C C
acetyl CoA
acetyl CoA
CAC
CAC

54. electron transport chain (ETC)
The ETC is located on the inner membrane of mitochondria
An enzyme called ATP synthase forms ATP by attaching a phosphate to ADP
ATP synthase is powered by the transfer of e- along a chain protein complexes that form the ETC.
ETC

55. electron transport chain (ETC)
The ETC produces ATP per glucose
Oxygen removes electrons from the final complex protein, so it is the final e- acceptor

57. Carbohydrate Metabolism
Carbohydrate molecules from foods can:
Enter catabolic pathways for energy production
Enter anabolic pathways for energy storage
React to form some of the amino acids
Excess glucose can be converted into and stored as:
Glycogen: Most cells, but liver
and muscle cells store the most
Fat to store in adipose tissue

58. catabolism of proteins, fats, & carbohydrates
Carbohydrates, Lipids & Proteins can be broken down and used for ATP synthesis
Most organic molecules enter the citric acid cycle as acetyl coA

59. DNA Replication & Protein Synthesis
Chapter 4.6
DNA Replication & Protein Synthesis

60. Definitions Gene: portion of DNA that encodes one protein
Genome: complete set of genetic instructions for an organism
Human genome = 20,000 genes on 23 pairs of chromosomes
Genetic (triplet) code: 3 letter DNA sequence that encodes for 1 amino acid

61. Genetic codes (triplets)

62. Properties of DNA DNA is a double-stranded helix
Chromatin is located within the nucleus

63. DNA is wrapped around histone proteins
Properties of DNA
DNA is wrapped around histone proteins

64. Deoxyribonucleic Acid (DNA)
Properties of DNA
Hydrogen bonds
Deoxyribonucleic Acid (DNA)
Anti-parallel configuration
The sugar in DNA is deoxyribose
Sugar-phosphate backbone
4 Nitrogenous Bases

65. Properties of DNA DNA contains 4 nitrogenous bases
Adenine (A) Thymine (T)
Guanine (G) Cytosine (C)
Adenine & Guanine are
Purines: 2 rings
Thymine & Cytosine are
Pyrimidines: 1 ring

66. Complimentary Base Pairs
A purine pairs with a pyrimidine
2 hydrogen bonds
3 hydrogen bonds

67. Complimentary strand:
Example of complimentary base pairs.
Original DNA strand:
C A C C T G G
G T G G A C C
Complimentary strand:

69. DNA Replication
S Phase
The Cell Replicates its DNA

70. DNA Replication
DNA replication is catalyzed by the enzyme DNA Polymerase

71. DNA Replication

72. Replication Fork

73. Replication Fork

74. DNA Replication new strand (green)
DNA replication is Semi-Conservative – One strand of the replicated DNA is new, the other is the original molecule.
original strand (teal)

75. DNA Replication
The two DNA molecules separate during mitosis

76. Transcription & Translation
Chapter 4.7
Transcription & Translation

77. RNA synthesis from DNA template
Transcription
RNA synthesis from DNA template

78. Properties of RNA single-stranded nucleic acid sugar = ribose
Uracil (U) replaces Thymine (T)
complimentary base pairs
A – U
G – C

79. RNA vs. DNA

80. There are several kinds of RNA
Messenger RNA (mRNA):
Conveys genetic information from DNA to the ribosomes
Transfer RNA (tRNA):
Transfers amino acids to the ribosomes during translation.
Ribosomal RNA (rRNA):
Provides structure and enzyme activity for ribosomes

81. Transcription Synthesis of a mRNA transcript from DNA template
Transcription is catalyzed by RNA Polymerase
Only 1 of the DNA strands is transcribed
mRNA undergoes further processing & leaves the nucleus

82. Properties of mRNA
Codon: 3 letter mRNA sequence that encodes for 1 amino acid.
start codon: Initiates protein synthesis (AUG = start codon)
stop codon: terminates translation (doesn’t code for an amino acid)

83. Properties of mRNA

84. Translation tRNA Amino acid 1
transfer RNA (tRNA) transports amino acid to mRNA
anticodon on tRNA aligns with codon on mRNA

85. Translation Ribosomes Translation occurs on Ribosomes in cytoplasm1
Amino acid
Ribosomes
Translation occurs on Ribosomes in cytoplasm
anticodon
codon
codon
mRNA

86. Translation

87. U A C 1
tRNA 3 2 A P A U G
mRNA

88. 3 2 U A C 1 A P A U G
mRNA

89. 3 3
peptide bond 1 2 A P U A C A U G
mRNA

90. 5 4
peptide bond 1 2 U A C 3 A P A U G
mRNA

91. 5 4
peptide bond 1 2 3 A P A U G
mRNA

92. 5
peptide bond 1 2 3 4 A P A U G
mRNA

93. 7 6
peptide bond 1 2 3 4 5 A P A U G
mRNA

94. 7 8
peptide bond 1 2 3 4 5 6 A P A U G
mRNA

95. 8
Polypeptide chain
STOP
CODON U G A A P
mRNA

96. Once translation is complete chaperone proteins
fold the protein into its configuration
post-translational modification
enzymes may further modify proteins after translation
phosphorylation – adding a phosphate to the protein
glycosylation – adding a sugar to the protein
End of Chapter 4

97. Attribution
Protein By Emw (Own work) [CC BY-SA 3.0 ( or GFDL ( via Wikimedia Commons.
Triglyceride By Wolfgang Schaefer (author) [Public domain], via Wikimedia Commons.
"Amylose 3Dprojection.corrected" by glycoform - Own work. Licensed under Public Domain via Commons -
"Beta-D-Glucose" by Yikrazuul - Own work. Licensed under Public Domain via Commons -
"Isomers of oleic acid" by Edgar181 - Own work. Licensed under Public Domain via Commons -
By Fir0002 [GFDL ( or CC-BY-SA-3.0 ( via Wikimedia Commons.
"Molecular-collisions" by Sadi_Carnot - Licensed under Public Domain via Commons -
Metabolic Pathways
Genetic Code By Madprime (Own work) [CC0, GFDL ( CC-BY-SA-3.0 ( or CC BY-SA ( via Wikimedia Commons
G-C Base Paring By Jypx3 (Own work) [Public domain], via Wikimedia Commons
A-T Base Paring By Jypx3 (Own work) [Public domain], via Wikimedia Commons
Citation: Sha, K. and Boyer, L. A. The chromatin signature of pluripotent cells (May 31, 2009), StemBook, ed. The Stem Cell Research Community, StemBook, doi/ /stembook
By No machine readable author provided. Masur assumed (based on copyright claims). [GFDL ( CC-BY-SA-3.0 ( or CC BY 2.5 ( via Wikimedia Commons
DNA Replication Split Horizontal I, Madprime [GFDL ( CC-BY-SA-3.0 ( or CC BY-SA ( via Wikimedia Commons
By OpenStax College [CC BY 3.0 ( via Wikimedia Commons
By OpenStax College [CC BY 3.0 ( via Wikimedia Commons
By Yikrazuul (Own work) [CC BY-SA 3.0 ( via Wikimedia Commons