Chapter 2 - SCHOOLinSITES

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Transcript Chapter 2 - SCHOOLinSITES

Chapter 2
Organic Chemistry
Organic Chemistry
• Is the study of all compounds that contain
bonds between Carbon atoms.
• Carbon compounds are also called
organic compounds.
Chemistry of living organisms
• Chemical elements are in living matter
– The cell is a chemical factory
– Carbon, Hydrogen, Oxygen and Nitrogen
• (C,O,H,N…most abundant in cells)
Chemistry of living organisms
• Small amounts of S, P, Mg, I, Fe, Ca, Na,
Cl and K are in cells.
– Sulfur, Phosphorus, Magnesium, Iodine, Iron,
Calcium, Sodium, Chlorine and Potassium
Chemical compounds in living
matter
• Inorganic
– Lack combination of carbon and hydrogen:
• Water
• Salts
• Inorganic acids and bases
Chemical compounds in living
matter
• Organic compounds
– Contain carbon and hydrogen
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Carbohydrates
Lipids
Proteins
Nucleic acids
All are called macromolecules or polymers.
Polymers are made of smaller subunits called
monomers.
Carbohydrates
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Contain C, H, and O
Mostly starches and sugars
H and O are present in a 2:1 ratio
Basic unit is a monosaccharide
– Glucose, C6H12O6
Two monosaccharides combine to form a
disaccharide in a process called dehydration
synthesis
Monosaccharides
“simple sugars”
• These molecules consist of open-chain or ring forms of 3
to 8 carbon atoms. The most common type of
monosaccharide is the simple sugar "glucose".
Examples of Monosaccharides
Disaccharides
• When two monosaccharides are joined together they form a
"disaccharide". This linking of two sugars involves the removal of a
molecule of H2O (water) and is therefore called a "dehydration
linkage". The reaction is called "dehydration synthesis".
• e.g. Glucose + Glucose = Maltose
Polysaccharide
• 2 or more monosaccharides
• The simplest polysaccharide is a long chain (polymer) of
glucose, called "starch".
Polysaccharides
• There are three types of starch:
• (1) Amylose: a non-branching straight
chain of glucose - used to store glucose in
plants.
• (2) Amylopectin: a branched chain, also
used to store glucose in plants.
• (3) Glycogen: another branched chain
molecule used to store glucose in animals.
Polysaccharides
• Polysaccharides can also form very important
structural components in plants and animals.
• Cellulose: is the principal constituent in plant
cell walls.
• Chitin: is an important structural material in the
outer coverings of insects, crabs, and lobsters.
In chitin the basic subunit is not glucose. These
polymers are made very hard when impregnated
with calcium carbonate.
Carbohydrate Review
o Monosaccharides or simple sugars include
glucose, fructose and ribose
o Disaccharides include maltose and
sucrose
o Polysaccharides include starch, cellulose,
chitin and glycogen
o Sugar names end in -ose
Carbohydrate Review
• Funtions
– Provide chemical energy, either as a polymer
(starch) or released and used as glucose
– Components of cell structures such as cell
wall in the case of cellulose
– Part of nucleic acid backbone, ribose
– Make outer coverings of animals with chitin
Lipids
• Contain C, H and O
• Ratio of hydrogen atoms to oxygen atoms
is greater than 2:1
• Ratio is not consistent
• Some lipids are products of dehydration
synthesis of 3 molecules of fatty acids and
one molecule of glycerol = Triglycerides
Lipids: glycerol + fatty acid
Lipids
• Very hydrophobic: hate water
• Examples: fats and oils, triglycerides and
phospholipids
• Functions: stored energy (triglycerides),
components of cell structures like the cell
membrane (phosopholipids and
cholesterol)
Proteins
• Contain C, H, O, N and sometimes sulfur
• Made of structural units called amino acids
(there are 20 AAs)
• Two amino acids combine by dehydration
synthesis to form a dipeptide. These are
joined by a peptide bond.
Proteins
• Amino acid + amino acid = protein chain or
polypeptide
• Form through synthesis and break down
through hydrolysis (addition of H2O)
• Proteins can be made of one or more
polypeptides
• Proteins differ in number, kinds and order of
amino acids
• Examples: insulin, hemoglobin and enzymes
Proteins
• Functions:
– Control the rates of reactions
– Regulate cell processes
– Help form bone and muscles
– Carry substances into and out of cells
– Help fight disease
Enzymes
• Are proteins
• Act as catalysts: speed things up
• Enzymes increase the rate of reactions by
decreasing the activation energy of
reactions
• Structure: large complex proteins made of
one or more polypeptide chains
• Names end in -ase
Enzymes
• Protein nature: either pure proteins or
proteins associated with non-protein parts
called coenzymes (vitamins)
• Active sites: enzymes are larger than their
target molecules and they fold to create
pockets where reacting molecules fit in
Animation of enzyme active site
• http://highered.mcgrawhill.com/sites/0072495855/student_view0/
chapter2/animation__how_enzymes_work.
html
Enzyme
• Functions to affect the rate of the
reactions. Makes it go faster
• Substrate is the beginning reactant in the
reaction
Enzymes
• Facts:
– Substrate binds to enzyme at active site
– Enzymes act on substrates to reduce energy
needed to make product
– Substrate is changed
– Enzyme separates from products and can
form an association with another substrate
– Enzyme, as a catalyst is not used up in the
reaction
– Increases reaction rate
Enzymes
• Lock and Key model: enzyme is compared
to key since only one key will open a lock
and enzymes are specific to one type of
substrate
Enzymes
• Factors that influences them:
– Temperature: increases temperate… goes
faster
• Optimum temp is when it is the most effective
• High temps denature (break down) the protein
Enzymes
• Also influenced by pH
– pH 3 best for stomach
– pH 8 best for intestines
– pH 7 best for cells and blood
Enzymes
• Amount of enzyme present also effects the
rate of the enzyme action
Nucleic Acids
• Contain H, O, N, C and phosphorus
• Are the monomers that make up nucleic
acids
• Each consists of a 5-C sugar, a phosphate
group and a nitrogenous base.
• Function: store and transmit hereditary
information
– Two kinds: DNA and RNA
Nucleic Acids
• Sugars vary between DNA and RNA
• DNA has deoxyribose
• RNA has ribose
Nucleic Acids
• Nitrogen bases vary between the two
• DNA has guanine, cytosine, adenosine,
and thymine
• RNA replaces thymine with uracil but the
others are the same
Nucleic Acids
• DNA’s nitrogenous bases always pair the
same.
• A-T and C-G
• RNA’s nitrogenous bases always pair the
same
• A-U and C-g
Quiz
1. Which group of organic molecules is the
build block of enzymes?
A. carbohydrates
B. proteins
C. lipids
D. nucleic acids
2. Which of the following carbohydrates is a
polysaccharide?
A. glucose
B. fructose
C. starch
D. sucrose
3. Which of the following macromolecules is
NOT connected properly with its subunit?
A. simple sugars – carbohydrate
B. amino acids – protein
C. fatty acids and glycerol – lipids
D. glucose – nucleic acids
4. What element is found in all organic
compounds?
A. nitrogen
B. carbon
C. iron
D. oxygen
5. The formation of a larger molecule from
two smaller molecules with the removal of
water is called?
A. hydrolysis
B. dehydration synthesis
C. metabolism
D. ion formation
6. DNA and RNA are two types of
A. carbohydrates
B. lipids
C. polysaccharides
D. nucleic acids
7. What is the function of enzymes?
A. they provide energy for chemical
reactions
B. they decrease the amount of activation
energy needed to begin a chemical
reaction
C. they transport food in the blood
D. they are chemically destroyed as they
break apart molecules in the cell
8. Which of the following factors affect the
rate of enzyme action?
A. pH
B. temperature
C. amount of enzyme present
D. all of these
9. which of the following is a type of
enzyme?
A. protease
B. lipase
C. amylase
D. all of the above
10. which material does the enzyme lactase
act upon?
A. lipids
B. proteins
C. lactose
D. amino acids
11. What is the name of the material that is
acted upon by enzymes?
A. coenzyme
B. inhibitor
C. substrate
D. fribrin
12. All enzymes are composed of
A. lipid molecules
B. sugar molecules
C. protein molecules
D. fatty acids
Answers
1. b
2. c
3. d
4. b
5. b
6. d
7. b
8. d
9. d
10. c
11. c
12. c