1. Cellular Metabolism

2. Introduction Cells are the site of metabolic reactions
Maintain life
Enzyme: controls each of the reactions
Specific type of protein

3. Metabolic Reactions
Anabolic: building up larger molecules from smaller ones
Materials for cell growth and repair
Catabolic: breakdown of larger molecules into smaller ones
Release energy

4. Anabolism
Dehydration Synthesis: -OH and –H from separate molecules are removed forming H2O
join sugar molecules into chains forming glycogen
Triglycerides in adipose cells
Proteins from amino acids
Peptide bonds

5. Dehydration Synthesis

6. Catabolism Hydrolysis: decomposes carbohydrates, lipids, and proteins
Splits water molecules
C12H22O11 + H2O  C6H12O6 + C6H12O6
Sucrose water glucose fructose
Occurs during digestion
Carbohydrates  monosaccharides
Fats  glycerol + fatty acids
Proteins  amino acids
Nucleic acids  nucleotides

7. Hydrolysis

8. Control of Metabolic Reactions
Most reaction require energy and a temperature greater than the body’s
Enzymes promote chemical reactions
Proteins that lower activation energy
Energy needed to begin a reaction
Catalysts
Never consumed  exist in small quantities

10. Enzymes Substrate: particular chemical enzymes act on
Catalaseenzyme: hydrogen peroxidesubstrate
Active Site: site on an enzyme where substrate binds
Lock and key
Very specific

11. Insulin Degrading Enzyme

12. Enzyme Reaction E+S ES  EP  E+P
S: Substrate
E: Enzyme
P: Product
Reaction Rate increases with increased substrate concentration

13. Factors that Alter Enzymes
Denature: protein structure fall apart and becomes nonfunctional
Too high temperatures
Radiation
Electricity
pH changes
Certain chemicals
Arsenic and Cyanides

14. Denatured Enzyme

15. Energy for Metabolic Reactions

16. Energy The capacity to change or move matter; Ability to do work Heat
Light
Sound
Electrical energy
Mechanical energy
Chemical energy

17. Release of Chemical Energy
Chemical energy is held in bonds and released when bonds are broken
Oxidation: cell burning glucose
Burning requires a large amount of energy to begin
Enzymes lower the activation energy
Most of the energy escapes as light or heat
Carry molecules capture about half of the energy
Remaining energy, heat, help maintain body temperature

18. Glycolysis 1st step in cellular respiration Cytoplasm or cytosol
Anaerobic: Doesn’t require oxygen
Energy is used to synthesize 2 ATP
6-C glucose 2 3-C pyruvic acid molecules

19. Aerobic Pathway Requires oxygen Occurs in the mitochondria
Products: CO2 & H2
CO2 diffuses out the cell
H2 combine with O2 to form H2O
Produces more 34 ATP

21. ATP vs. ADP ATP: adenosine triphosphate ADP: adenosine diphosphate
3 phosphates
Fully charged battery
Break last phosphate off  release energy
ADP: adenosine diphosphate
2 phosphates
Partially charged battery
Energy + phosphate  store energy

22. Metabolic Pathway
Anabolic and catabolic reaction happen in particular sequence
Enzymes that control the reaction rates must also act in a specific sequence
Enzymes are positioned in the exact sequence as that of the reaction

23. Pathways Carbohydrates: cellular energy source
Cellular respiration
Glycolysis Citric Acid Cycle Electron Transport Chain
Half of the energy(E)  ATP; remaining E heat
Lipid: phospholipids, cholesterol, triglycerides
2x E gram per gram than carb. And protein
Beta Oxidation: form ketone bodies that can be used in the citric acid cycle
Acetone

25. Protein Pathway
Amino acids are absorb and transported by the blood to cells
Amino acids are reunited into cell parts
Deamination: amino acids have N removed
Used in citric acid cycle
By product: urea
liver

26. Metabolic Pathways

27. Nucleic Acids and Protein Synthesis27

28. Genetics In the nucleus, DNA is housed
information from parent to child
Gene
instruction for proteins
Enzymes and control metabolic processes

29. Karyotype

30. DNA Molecule Double Helix Nucleotides Sugar phosphate backbone
Nitrogenous bases in the middle
A,T,G,C
2 strands bonded by H-bonds
A pairs with T, and G pairs with C
One DNA molecule: millions of base pairs long

31. Genetic Code DNA: specific nucleotide sequence
Specifies a specific amino acid
RNA molecules transfer information to cytoplasm

32. RNA Single stranded Contain uracil instead of thymine
Contain ribose instead of deoxyribose
mRNA: messenger, carries a copy of a single gene
rRNA: composes ribosomes
tRNA: transfers amino acids

33. Protein Synthesis Transcription Single genes are coped into mRNA
Sent into the cytoplasm to a ribosome

34. Transcription

36. Protein Synthesis Translation
At ribosome, mRNA is read by codons, 3 bases
Amino acids are brought to the ribosome by the tRNA
Anticodons on the tRNA must match the codons on the mRNA
mRNA: UUA CGC AUC GAU
tRNA: AAU GCG UAG CUA
Amino acid released from tRNA form a chain and then a protein

39. DNA Synthesis Each cell needs a copy of DNA
During interphase, the DNA is replicated
The double helix unzip
Hydrogen bonds break
Bases are brought in to each strand
Semiconservative: each DNA molecule contains a new and an old strand of DNA

40. DNA Replication