1. Chapter 3: Biochemistry
Ms. Mezzetti
Lynn English High School
Science Department

2. Warm up:
Define biochemistry
What does “Chemistry of Life” mean?

3. Objectives: Students will be able to:
Distinguish between organic and inorganic compounds.
Explain the importance of carbon bonding in biological molecules.
Summarize how large carbon molecules are synthesized and broken down.
Describe how the breaking down of ATP supplies energy to drive chemical reactions.

4. Carbon
Organic compounds contain carbon atoms and are found in living things.
Therefore, all living organisms contain carbon
Most inorganic compounds do not contain carbon atoms.

5. Carbon Bonding Carbon atoms can form: four covalent bonds
single, double and triple bonds
ring, branched or straight chains

6. Carbon Compounds Monomers: subunit of larger molecules
Polymer: 3 or more monomers

7. Monomers/Polymers
Monomer: Polymer:
Monomer: Polymer:

8. Condensation Reactions/Hydrolysis
Condensation Reactions remove water and combine monomers to make polymers
Hydrolysis break down polymers into smaller macromolecules and monomer

9. Energy for life
Adenosine triphosphate (ATP) stores and releases energy during cell processes, enabling organisms to function.
ATP is the fuel/energy for life!

10. Organic Molecules Objectives: Students will be able to:
Identify the 6 most abundant elements of life are
C-H-N-O-P-S
Distinguish 3 types of carbohydrates-monosaccharide's, disaccharides and polysaccharides.
Explain how enzymes are a type of protein and catalyze chemical reactions.
Identify the monomers and polymers of carbohydrates, proteins, lipids and nucleic acids.
Compare the nucleic acids DNA and RNA.

11. 6 Most abundant elements in nature
Carbon
Hydrogen
Nitrogen
Oxygen
Phosphorus
Sulfur

12. 4 Classes of Organic Compounds
We classify the major organic compounds into 4 groups:
Carbohydrates
Proteins
Lipids
Nucleic acids

13. Carbohydrates: Sugars and Starches
composed of carbon, hydrogen, and oxygen in a 1:2:1 ratio- CH2O
Used as short term energy
End in ‘ose
Animals store energy as glycogen
Plants store energy as starch
Plant cells made of cellulose
Fungi cell walls contain chitin

14. Carbohydrates Monosaccharide's
The monomers of carbohydrates are called monosaccharide's, simple sugars such as glucose, fructose and galactose
Disaccharides
Two monosaccharide's join to form a double sugar called a disaccharide such as sucrose (glucose + fructose) and lactose
Polysaccharides
Three or more monosaccharide's join to form large macromolecules such as starches, cellulose, chitin & glycogen. These are complex carbohydrates

15. Proteins
Proteins are organic compounds composed mainly of carbon, hydrogen, oxygen, and nitrogen.
C-H-O-N
Proteins have many functions: --structural-such as muscle fiber collagen & keratin, defensive-antibodies, and catalytic roles-enzymes.
Found in

16. Proteins
Amino Acids: Proteins are made up of monomers called amino acids.
There are 20 different types identified by their R group.
Dipeptides: Two amino acids are joined by peptide bonds to form a dipeptide.
Polypeptides: A long chain of amino acids is called a polypeptide. Usually 1000’s of amino acids joined together by peptide bonds.

17. Amino Acids
There are 20 different amino acids. Each is different depending on it’s R group.

18. Structure of Proteins Primary-single chain of amino acids
4 Structures of proteins:
Primary-single chain of amino acids
Secondary- chains become folded or helical
Tertiary-chains bend
Quaternary-globular

19. Proteins
Enzymes:
are globular proteins that speed up chemical reactions and reduce the amount of activation energy needed for the reaction.
There are 2200 different types of enzymes that catalyze 2200 specific types of reactions
End in ‘ase: catalase, amylase, lipase are examples
Enzymes are affected by pH, temperature and salinity

20. Enzyme Activity

21. Lipids Fatty Acids-building blocks of lipids (monomers)
they have a hydrophilic (water loving) end and a hydrophobic (water fearing) end.
Triglycerides
Triglycerides consist of three fatty acids and one molecule of glycerol.

22. Lipids Lipids are: nonpolar molecules that store long term energy
are an important part of cell membranes.
Fats are a type of lipid:
saturated (animal fat/solids/lard)
unsaturated (fats from plants-oils/liquid)
Carbons are full
Single bonded
Carbons not full
Double bonded

23. Lipids
Phospholipids: make up cell membranes; have a polar head and nonpolar tail
Waxes: A wax is made of one long fatty acid chain joined to one long alcohol. Protect animal ears and plant leaves.
Steroids: A steroid is a lipid composed of four fused carbon rings that help regulate body functions-testerone and estrogen Cholesterol is a steroid found in cell membranes that contributes to its permeability (letting things in and out)

24. Nucleic Acids Nucleotide
A nucleic acid is a large and complex organic molecule that stores and transports information.
The monomers , building blocks of nucleic acids are nucleotides.
Nucleotides contain a 5-carbon sugar, nitrogenous base and a phosphate group

25. Nucleic Acids - DNA DNA- deoxyribonucleic acid (DNA)
Stores genetic information for cell activities.
Is double stranded (helix)
Has nitrogenous bases
adenine,
thymine,
guanine
cytoseine

26. Nucleic Acids - RNA RNA- ribonucleic acid
Important for protein synthesis.
Is single stranded
It’s nitrogenous bases
adenine,
uracil
guanine
cytoseine

27. Multiple Choice
1. Which of the following is not a function of polysaccharides? A. energy source B. energy storage C. structural support D. storage of genetic information

28. Multiple Choice, continued
2. Which of the following statements is false? F. A wax is a lipid. G. Starch is a lipid. H. Saturated fats are solid at room temperature. J. Unsaturated fats are liquid at room temperature.

29. Multiple Choice, continued
3. Which of the following molecules stores hereditary information? A. ATP B. DNA C. protein D. carbohydrates

30. Multiple Choice, continued
4. What is the name of the molecule in plants that stores sugars? A. starch B. protein C. cellulose D. glycogen

31. Multiple Choice, continued
The figure below illustrates
the basic structure of a cell membrane. Use the
figure to answer the questions that follow.
5. Which of the following molecules make up the basic structure of a cell membrane?
A. waxes
B. steroids
C. fatty acids
D. phospholipids

32. Multiple Choice, continued
The figure below illustrates
the basic structure of a cell membrane. Use the
figure to answer the questions that follow.
6. The “tails” of the molecules in the figure orient away from water. Which of the following describes the tail’s movement away from water?
F. polar
G. adhesive
H. hydrophilic
J. hydrophobic

33. Multiple Choice, continued
7. simple sugars : carbohydrates :: amino acids :
A. lipids
B. proteins
C. nucleic acids
D. amino acids

34. Short Response, continued
Proteins are affected by environmental conditions such as heat and pH.
Explain why the process of cooking an egg cannot be reversed.
Answer:
The heat that is added to the egg changes the bonds in the proteins and other molecules that make up the egg to such a large extent that the original protein shape can no longer be distinguished.

35. Open Response Enzymes are essential for the functioning of all cells.
Part A Explain what enzymes do that is essential for cell function.
Part B Explain the induced fit model of enzyme action.
Answer:
Part A Enzymes catalyze chemical reactions that are involved in important cell processes.
Part B Bonding of the substrates to enzymes causes a slight change in the enzyme’s shape, thereby weakening some of the bonds and lowering activation energy.

36. Any Questions?