1. B I O C H E M I S T R Y Basic Chemistry and the
B I O C H E M I S T R Y
Basic Chemistry and the
Chemical Compounds of Life
Regents Biology

2. Upon completion of this unit students will be able to:
OBJECTIVES
Upon completion of this unit students will be able to:
1. Define biochemistry.
2. Differentiate empirical, molecular and structural formulas.
3. List the 4 most common elements found in living things.
4. Explain the differences between inorganic and organic compounds.
5. Understand that water is the most important inorganic compound for organisms.
6. State the functions of carbohydrates.
7. Understand that monosaccharides (i.e., glucose) is the building block for all carbohydrates.
8. Recognize the chemical formula for carbohydrates and chemical structure of glucose.
9. List several examples of carbohydrates.
10. Recognize that most carbohydrates end in –ose.
11. Explain the difference between a ribose sugar and a deoxyribose sugar.
12. Differentiate between a monosaccharide, disaccharide, and polysaccharide.
13. List three examples of polysaccharides and state their functions.
14. State the functions of lipids in the body.
15. Understand that a lipid molecule is made up of 3 fatty acids and 1 glycerol molecule.
16. List several examples of lipids.
17. Identify the two types of nucleic acids.
18. Differentiate DNA and RNA by structure and function.
19. Understand that amino acids are the building blocks of proteins.
20. Recognize the chemical formula and structure of an amino acid.
21. State that the chemical bond that links one amino acid to another is called a peptide bond and
that two amino acids combined is called a dipeptide.
22. Explain what is meant by a dipeptide and a polypeptide and explain how they are formed.
23. List five examples of polypeptides.
24. Explain in a sentence or two why there are so many possible kinds of proteins.
25. Recognize that a protein structure determines its function.
26. Understand the structure and function of an enzyme and that they usually end in –ase.

3. KEY WORDS 1. active site 2. amino acid 3. amino group 4. carbohydrates
1. active site
2. amino acid
3. amino group
4. carbohydrates
5. catalyst
6. dehydration synthesis
7. dipeptide
8. disaccharide
9.    DNA
10.  enzyme
11.  hydrolysis
12.  lipid
13.  monosaccharides
14.  nucleic acid
15.  nucleotide
16.  organic compound
17.  peptide bond
18.  polymer
19.  polypeptide
20.  polysaccharide
21.  protein
22.  RNA
23.  starch
24.  substrate

4. INTRODUCTION
The processes of life (metabolism, excretion, etc.) are, for the most part, CHEMICAL
There are only about 100 different ATOMS AND ELEMENTS, which is what matter is made up of.
Examples CARBON, HYDROGEN, etc.
Biochemistry is THE STUDY OF ATOMS AND MOLECULES THAT ARE IMPORTANT FOR LIFE

5. CHEMICAL ELEMENTS and FORMULAS
Remember that CELLS are the basic unit of life?
Well, cells as well as everything nonliving in this world, are made up of ATOMS of elements.
There are 3 different ways to express the amount or ratios of atoms present in a molecule:
Empirical formula – formula showing SIMPLEST proportions of atoms in a compound
Ex.: CH
Molecular formula – formula showing the EXACT COMPOSITION of a compound
Ex.: C2H2
Structural formula – Shows number and kind of atoms AND how they are BONDED TO EACH OTHER
Ex.: H-C=C-H

6. INORGANIC vs. ORGANIC COMPOUNDS
ALL organisms are made up of both ORGANIC and INORGANIC compounds. So what’s the difference?
A. Inorganic Compounds
The MOST important inorganic compound for living things is H2O because we need it to live.
Many of the biological processes that are necessary for life take place in water.
In fact, we are made up of over 65 percent water and can really only survive for a few days without water!!!
Inorganic molecules DO NOT CONTAIN CARBON

7. C-H-O-N B. Organic Compounds
Of all of the atoms found on earth, there are four main ones that are present in living things. The four main elements that are present in organic compounds are:
ELEMENT
SYMBOL
CARBON C
HYDROGEN H
OXYGEN O
NITROGEN N
C-H-O-N

8. ·      The element that is FAMOUS for being found in organic compounds is CARBON
it can bond to 4 things which makes it possible for there to be so many organic compounds.   C

9. TYPES OF ORGANIC COMPOUNDS
·      There are 4 types of organic compounds. They are:
ORGANIC COMPOUNDS
COMPOSITION
FUNCTION(S)
CARBOHYDRATES
C, H, O
SOURCE OF
ENERGY
LIPIDS
CUSHIONING,
INSULATION, ENERGY
NUCLEIC ACIDS
C, H, O, N, P
DIRECT AND CONTROL ACTIVITIES
PROTEINS
C, H, O, N
STRUCTURE AND FUNCTION

10. CARBOHYDRATES I. Structure & Function
Carbohydrates are comprised of CARBON, HYDROGEN, AND OXYGEN in a ratio of 1:2:1.
Ex. Glucose C6H12O6
The chemical names of carbohydrates usually end in –OSE (i.e., glucose, sucrose, etc.)
MONOSACCHARIDES are the simple sugars

11. STORES EXCESS SUGAR IN HUMANS
     ·      Sugars are biologically important because they CONTAIN LARGE AMOUNTS OF ENERGY; nearly all organisms use glucose as a source of energy.
NAME
FORMULA
TYPE
FUNCTIONS
Glucose
C6H12O6
MONOSACCHARIDE
ENERGY
Maltose
C11H22O11
DISACCHARIDE
“ “
Lactose
Disaccharide
Sucrose
Cellulose
POLYMER
POLYSACCHARIDE
TOUGH OUTER STRUCTURE
Glycogen
Polysaccharide
STORES EXCESS SUGAR IN HUMANS
Starch
STORES EXCESS SUGAR IN PLANTS

12.  Some up-close-and-personal looks at some Carbohydrates:
GLUCOSE
SUCROSE

13. A. CARBOHYDRATES II. Dehydration Synthesis
Sugar molecules can be bonded together by a process called DEHYDRATION SYNTHESIS
Synthesis means “PUTTING TOGETHER” and dehydration means “REMOVING WATER”.
Dehydration synthesis makes ORGANIC COMPOUNDS that the organism needs,
such as GLYCOGEN & PROTEINS.
We use it for ALL complex organic compounds.

14. By joining two simple sugars, a DISACCHARIDE is formed:

15. A. CARBOHYDRATES Polysaccharides
Polysaccharides are LONG CHAINS OF REPEATING SUGAR UNITS
can be formed by DEHYDRATION SYNTHESIS
Organisms store excess sugar in the form of polysaccharides:
1. PLANTS – STARCH
2. HUMANS – GLYCOGEN (IN LIVER AND MUSCLES)
Polysaccharides can also be used to form tough, structural parts of organisms:
1. PLANTS - CELLULOSE
2. INSECTS - CHITIN

16. CARBOHYDRATES III. Hydrolysis
Just as sugar molecules can be joined together, they can be broken apart.
Hydrolysis: WATER BEING ADDED TO SPLIT UP A COMPLEX MOLECULE THAT WAS FORMED FROM DEHYDRATION SYNTHESIS

17. B. LIPIDS I. Structure & Function
Lipids are commonly called FATS, OILS AND WAXES
Lipids are comprised of CARBON, HYDROGEN, AND OXYGEN, as carbohydrates are.
The only difference is that THE RATIOS ARE DIFFERENT
AS A RESULT FATS YIELD MORE ENERGY
A molecule of fat is formed from the combination of FATTY ACIDS AND GLYCEROL

18. Dehydration Synthesis

19. Mammals also use lipids for CUSHIONING AND INSULATION
Lipids functions
BEING A RESERVE ENERGY SUPPLY
PART OF THE CELL MEMBRANE
Lipids contain TWICE as much energy as the same amount of carbohydrate!
Mammals also use lipids for CUSHIONING AND INSULATION

20. B. LIPIDS II. Saturated vs. Unsaturated Fats
Saturated fat: ALL CARBON-TO-CARBON BONDS ARE SINGLE BONDS
C-C-C-C-C-C-C-C-C-C-C-C-C
 Unsaturated fat: ONE OR MORE PAIRS OF CARBON ATOMS ARE JOINED BY A DOUBLE OR TRIPLE BOND
Unsaturated fats are liquid at room temperature and are healthier for you than saturated fats which are solid at room temperature

21. C. PROTEINS I. Structure & Function
Proteins are compounds that CONTAIN CARBON, HYDROGEN, OXYGEN AND NITROGEN
The functions of proteins are:
STRUCTURAL PARTS OF CELLS AND BODY TISSUES (HAIR, NAILS, CARTILAGE)
PIGMENTS IN BLOOD, SKIN, EYES, AND CHLOROPHYLL
HORMONES (CHEMICAL MESSENGERS)
ENZYMES

22. C. PROTEINS II. Amino Acids
Amino acids are THE BUILDING BLOCKS OF PROTEINS
Each amino acid is called a MONOMER. The structure of an amino acid is:
There are 20 different amino acids that are found as part of proteins.
Amino acids can be linked together in any sequence and in chains of varying length.
The R group is variable or RANDOM

23. C. PROTEINS III. The Peptide Bond
Two amino acids may be bonded together by DEHYDRATION SYNTHESIS TO MAKE A DIPEPTIDE
The bond that forms is called a PEPTIDE BOND
It forms between THE AMINO GROUP OF ONE AMINO ACID AND THE CARBOXYL GROUP OF THE NEXT
A chain of amino acids is called a POLYPEPTIDE. All proteins are made up of POLYPEPTIDES (CHAINS OF AMINO ACIDS).

24. ENZYMES ARE PROTEINS…………..
Enzymes are PROTEIN SUBSTANCES THAT MAKE CHEMICAL REACTIONS OF LIVING ORGANISMS POSSIBLE
Enzymes enter into a chemical reaction TEMPORARILY—JUST LONG ENOUGH TO MAKE IT HAPPEN
Enzymes are CATALYSTS, WHICH MEANS THEY ARE NOT CHANGED DURING A REACTION,
THEY ARE USED AGAIN AND AGAIN (RECYCLED)
The substance that an enzyme acts on is called its SUBSTRATE
Enzymes usually end with the suffix -ASE.
Examples: maltase, amylase, lactase and protease

25. How Enzymes Work
The ability of enzymes act as CATALYSTS depends on their SHAPE
There is a region on the surface of an enzyme called the ACTIVE SITE
The substrate molecules fit the shape of the active site
when the substrate comes into contact with the active site, it forms a TEMPORARY UNION CALLED THE ENZYME-SUBSTRATE COMPLEX
ENZYME-SUBSTRATE COMPLEX
the enzyme may cause the substrate to separate into two molecules
may also join two molecules (using two substrates)
The theory of enzyme action where the enzyme and substrate fit together at an active site is called the LOCK-AND-KEY MODEL

26. LOCK AND KEY MODEL
THE SHAPE OF THE ACTIVE SITE OF THE ENZYME ONLY FITS THE SHAPE OF CERTAIN SUBSTANCES
EACH ENZYME CAN ONLY CATALYZE CERTAIN SUBSTRATES

27. D. NUCLEIC ACIDS
Nucleic acids contain the elements CARBON, HYDROGEN, OXYGEN, NITROGEN and PHOSPHORUS.
There are two kinds of nucleic acids which were originally found in the part of the cell called the nucleus:
DNA – DEOXYRIBONUCLEIC ACID
RNA – RIBONUCLEIC ACID
DNA is the hereditary material passed from one generation to the next during reproduction.
RNA works with DNA to direct and control the development and activities of all cells of an organism.
The building blocks of nucleic acids are NUCLEOTIDES.

28. D. NUCLEIC ACIDS I. Structure of DNA and RNA
The general structure of a nucleic acid molecule is that of A LONG CHAIN OF REPEATING UNITS
In DNA, there are 4 different bases that can be attached to the chain:
ADENINE (A), GUANINE (G), CYTOSINE (C), THYMINE (T)
The sequence of bases acts as a CODE or TEMPLATE
determines what proteins will be made in the cell.
The proteins then determine the nature of the cell what activities the cell will undertake.
The entire DNA molecule is coiled into a DOUBLE HELIX.
By repeated coilings DNA is “packed” and is able to fit into tiny structures within the cell.

29. An RNA molecule is similar to a DNA molecule, but it has some differences.
The structure of an RNA molecule is different than the structure than a DNA molecule by:
RNA CONSISTS OF A SINGLE STRAND OF BASES
THE SUGAR IN RNA IS RIBOSE
THYMINE IS REPLACED WITH URACIL
Look at the difference!