Transcript 2b Chem Organic notes

2-3 -- 2-4: Biochemistry
pgs. 44-53
Section 2-3

2–3
Carbon Compounds
A. The Chemistry of Carbon
B. Macromolecules
1. Carbohydrates
2. Lipids
3. Nucleic Acids
4. Proteins
Biochemistry

Organic chemistry is the study of all compounds that
contain carbon

Biochemistry is the study of compounds that contain
carbon found in the body

We will be studying proteins, lipids, nucleic acids,
and carbohydrates (all contain carbon and are found
in the body)
The Chemistry of Carbon

A carbon atom has four electrons available for bonding
in its outer energy level. In order to become stable, a
carbon atom forms four covalent bonds that fill its
outer energy level (needs 4 valence electrons)

Carbon can combine with hydrogen, oxygen,
phosphorus, sulfur, and nitrogen in the body

Two carbon atoms can form various types of covalent
bonds—single, double or triple.
Single Bond
Double Bond
Triple Bond
Section 2-3

Carbon compounds vary greatly in size.
 When carbon atoms bond to each other, they
can form straight chains (linear), branched
chains, or rings (circular)
Methane
Acetylene
Butadiene
Benzene
Isooctane
Cyclic
Branched &
double
bonded
Linear &
triple bond
Linear &
single bonded
Linear and
branched
Building Molecules- formation and
breaking of chemical bonds
Monomers – small building block molecules;
used to build larger molecules; linked to
each other by covalent bonds (glucose)
Polymers – molecules formed by linking three
or more monomers; also called
macromolecules
(starch and protein)
Molecular chains
Small molecules bond together to form
chains called polymers. A polymer is a
large molecule formed when many
smaller molecules bond together.
Hydrolysis
Dehydration
synthesis
Macromolecules
 Polymers or “giant compounds” in our living cells
 Made of 1000’s and 100,000’s smaller molecules
(monomers)
 Formed by polymerization- large compounds built by
joining smaller ones
 Monomers can be different like beads in a multicolored
necklace (polymer)
 4 groups of organic compounds that are macromolecules
found in living things are:
–
–
–
–
Carbohydrates
Lipids
Nucleic acids
Proteins
Section 2-3
Macromolecules
Carbon
Compounds
include
Carbohydrates
Lipids
Nucleic acids
Proteins
that consist of
that consist of
that consist of
that consist of
Sugars and
starches
Fats and oils
Nucleotides
Amino Acids
which contain
which contain
which contain
which contain
Carbon,hydrogen,
oxygen, nitrogen,
phosphorus
Carbon,
hydrogen,oxygen,
nitrogen,
Carbon,
hydrogen,
oxygen
Carbon,
hydrogen,
oxygen
Carbohydrates
 A carbohydrate is a
biomolecule composed of
carbon, hydrogen, and oxygen
with a ratio of about two
hydrogen atoms and one
oxygen atom for every carbon
atom.
 Main energy source for living
things
 The simplest type of
carbohydrate is a simple sugar
called a monosaccharide. (ie.
glucose, fructose (fruits),
galactose (milk)
– Breakdown of glucose in
body is an immediate
energy source for cell’s
activities
Carbohydrates
 The largest carbohydrate molecules are polysaccharides,
polymers composed of many monosaccharide subunits. (ie.
potatoes, liver)
 Polysaccharides are extra sugars stored as complex
carbohydrates like glycogen, starch, and cellulose; used for
fuel, energy storage, and support
– starch - composed of glucose monomers; energy storage for
plants; provides most of the food for the world’s people
– glycogen - branched glucose monomers; energy storage in
animals; usually stored in muscles and liver
– cellulose - composed of linear chains of glucose monomers
that are cross-linked with each other; provides support for
plant’s cell walls; most abundant organic molecule on
Earth; “fiber” in diet of animals
Cows have a bacteria in their digestive system that
hydrolyzes the cellulose for them
Starch Molecule- made up of glucose monomers
Section 2-3
(usually identified by –OH and many carbons)
Starch molecule
Glucose
Glucose
monomer
3 polysaccharides
Affect of Soap

http://www.chemistry.nus.edu.sg/2500/soap
.htm
Lipids
 Lipids are large biomolecules that are made mostly of carbon and
hydrogen with a small amount of oxygen, and sometimes
phosphorus
 They are insoluble in water because their molecules are nonpolar
and are not attracted by water molecules
 4 categories:
– Fats- store long term energy (saturated and unsaturated)
– Waxes- waterproof coverings (feathers, cuticle, apple peel)
– Phospholipids- makes up cell membrane to help move
materials in and out of cell
– Steroids- includes hormones- produced in one part of body to
control functions in another part of body (estrogen and
testosterone)
 Building blocks or monomers are glycerol and fatty acids (1:3)
Phospholipids
-Lipids that contain phosphate
-Major component of cell membranes
-Helps control movement of materials
in and out of cell
Fat
Nucleic Acids - DNA and RNALarge, complex molecules composed of nucleotides
3 parts of a nucleotide
1) phosphate group
2) five-carbon sugar
DNA = deoxyribose
RNA = ribose
3) nitrogenous base
DNA = adenine(A),
thymine(T),
guanine(G),
cytosine(C)
RNA = A, G, C
uracil(U)
phosphate
base
sugar
Nucleotide monomers (which
make up DNA and RNA)join
by dehydration synthesis
combining the sugar group of
one nucleotide with the
phosphate group of another
Hydrogen bonding
between nitrogenous
bases is responsible
for the final structure
of DNA

Purposes and Differences
DNA
– forms a double stranded helix made
of two strands of nucleotides
– contains instructions to control cell’s
activities (heredity) and is used to
form proteins
– in nucleus
– bases are A, T, C, G; deoxyribose
sugar

RNA
– forms a single strand of nucleotides
– carries instructions from DNA to
ribosome to make proteins
– moves from nucleus into cytoplasm
– nitrogenous bases are A, U, C, G
(not T); ribose sugar
DNA
Proteins
 a large, complex polymer composed of carbon,
hydrogen, oxygen, nitrogen, and sometimes sulfur
 building blocks (monomers) are amino acids
– Amine group (-NH2), carboxyl group (-COOH), H, R
group that is specific to each amino acid
 There are about 20 common amino acids that can make
literally thousands of proteins
Amino
Acid:
general
structure)
Protein- composed of amino acids
R group
Section 2-3
Amino Acid Examples
General structure
Alanine
Serine
Section 2-3
Amino Acid Examples
Carboxyl group
General structure
Alanine
Serine
Section 2-3
Amino Acid Examples
Carboxyl group
General structure
Alanine
Serine
The structure of proteins


Peptide bonds
are covalent
bonds formed
between amino
acids to build a
protein
Figure 2-17 A Protein
Proteins are
the building
blocks of many Amino
structural
acids
components of
organisms.
The sequence of amino acids determines
the function of the protein
 Essential to the structure and activities of life
– Movement (actin and myosin)
– Structural (collagen, keratin)
– Transport (hemoglobin)
– Storage (casein)
– Regulation (hormones-insulin)
– Defense (antibodies)
– Biochemical control (enzymes)
Section 2-3
Macromolecules
Carbon
Compounds
include
Carbohydrates
Lipids
Nucleic acids
Proteins
that consist of
that consist of
that consist of
that consist of
Sugars and
starches
Fats and oils
Nucleotides
Amino Acids
which contain
which contain
which contain
which contain
Carbon,hydrogen,
oxygen, nitrogen,
phosphorus
Carbon,
hydrogen,oxygen,
nitrogen,
Carbon,
hydrogen,
oxygen
Carbon,
hydrogen,
oxygen
Section 2-4
2–4 Chemical Reactions and Enzymes
A.Chemical Reactions
B.Energy in Reactions
1. Energy Changes
2. Activation Energy
C.Enzymes
D.Enzyme Action
1. The Enzyme-Substrate Complex
2. Regulation of Enzyme Activity
Chemical Reactions
 Living things are made up of chemical compounds
 Chemistry isn’t just what life is made of, it is also what life does
– Organism’s growth interactions, reproduction, movement are
all based on chemical reactions
 Chemical reaction- process that changes one set of chemicals into
another set of chemicals
– Some slow- iron + oxygen--- iron oxide or rust
– Some quickly- hydrogen gas + oxygen--- explosive
 Reactant- elements or compounds that enter the chemical reaction
 Product- elements or compounds that are produced by reaction
HCl + NaOH
NaCl + H2O
reactants
shows
products
direction
of change
Chemical reactions always involves breaking and forming of new bonds
Chemical Reaction in Your Body
 Your cells produce carbon dioxide (normal)
 Carbon dioxide is carried to lungs through blood
 Then exhaled
 But carbon dioxide is not soluble in water
 So in the blood, carbon dioxide and water form carbonic
acid (very soluble in water)
CO2 + H2O
H2CO3
 This chemical reaction allows blood to carry CO2 to the
lungs
 Then the reaction reverses to produce CO2 to be exhaled
from lungs and water absorbed back into body
H2CO3
CO2 + H2O
Energy in Reactions – chemical reactions involve breaking
and forming bonds which releases or absorbs energy
1)
Two types of Energy Changes
Endothermic -- reactions in which energy is
absorbed (feel no heat); temp goes down
glucose + fructose + energy
Temp
2)
sucrose + water
Temp
Time
Time
Exothermic -- reactions in which energy is
released; take place in cells of your body to
produce energy needed for everything you do
and to heat your body; temp goes up
glucose + oxygen
carbon dioxide + water + energy
So for us to stay alive, we must carry out
reactions that require energy so we have a
source of energy to carry out chemical reactions
– Plants get energy from sunlight
– Animals get energy from food eaten
Enzymes
To make sure our body’s chemical reactions
occur at a rate that our body needs, cells make
catalysts
– A catalyst is a substance that speeds up the rate of a
chemical reaction without being changed by the
reaction
– Enzymes are proteins that act as a biological catalyst
– Enzymes speed up chemical reactions that take place
in our cells
Ex- carbonic anhydrase is an enzyme that removes carbon
dioxide from your blood quickly into the lungs
– Enzymes are specific in which reaction they catalyze
Enzyme Action

http://www.northland.cc.mn.us/biology/Biol
ogy1111/animations/enzyme.html

http://www.lewport.wnyric.org/jwanamaker
/animations/Enzyme%20activity.html



Enzyme ActionEnzyme-Substrate Complex
Substrate- substance needed to be broken down
Active site- area on enzyme that is specific for and exactly
fits the shape of the substrate (lock and key)
– Substrate combines to enzyme’s active site
– Enzyme breaks down substrate into products and releases
them into the cell
– Enzyme can be reused again
– Ex- substrate sucrose + enzyme sucrase
glucose +
fructose
Enzymes are catalysts and can be affected by pH and temp.
changes in the body, and chemical reactions
– Ex- enzymes that digests food works best at a specific pH
– Ex- enzymes in body work best at temperature around
37oC
Figure 2-21 Enzyme Action
Section 2-4
Enzyme
(hexokinase)
Glucose
Substrates
Products
ADP
Glucose-6phosphate
Products
are released
ATP
Active site
Enzyme-substrate
complex
Substrates
are converted
into products
Substrates
bind to
enzyme
Figure 2-21 Enzyme Action
Enzyme
(hexokinase)
Glucose
Substrates
Products
ADP
Glucose-6phosphate
Products
are released
ATP
Active site
Enzyme-substrate
complex
Substrates
are converted
into products
Substrates
bind to
enzyme
Figure 2-21 Enzyme Action
Section 2-4
Enzyme
(hexokinase)
Glucose
Substrates
Products
ADP
Glucose-6phosphate
Products
are released
ATP
Active site
Enzyme-substrate
complex
Substrates
are converted
into products
Substrates
bind to
enzyme
Figure 2-21 Enzyme Action
Section 2-4
Enzyme
(hexokinase)
Glucose
Substrates
Products
ADP
Glucose-6phosphate
Products
are released
ATP
Active site
Enzyme-substrate
complex
Substrates
are converted
into products
Substrates
bind to
enzyme
Question 1
How many covalent bonds does a carbon atom
need to form in order to become stable?
a. 1
b. 2
c. 3
d. 4
The answer is D. A carbon atom has 4
electrons available for bonding in its outer
energy level and needs to form 4 covalent
bonds in order to become stable.
Question 2
A _____ is a biomolecule composed of carbon,
hydrogen, and oxygen with a ratio of about 2
hydrogen atoms and 1 oxygen atom for every
carbon atom. It also is used for long-term energy
and waterproofing.
a.
b.
c.
d.
carbohydrate
lipid
protein
lipid (fatty acid)
The answer is D. Lipids are made mostly of
carbon and hydrogen, and proteins contain
nitrogen in addition to carbon, hydrogen, and
oxygen.
Question 3
In which type of molecule will you find peptide bonds?
a. carbohydrate
b. lipid
c. protein
d. nucleic acid
The answer is C. Amino acids are the basic
building blocks of proteins and are linked
together by peptide bonds.
Question 4
What biomolecule is represented in this diagram?
a. carbohydrate
b. nucleotide
c. protein
d. lipid
The answer is B. Nucleotides are the smaller
subunits that make up nucleic acids. Nucleotides
are composed of three groups: a nitrogenous
base, a simple sugar, and a phosphate group.
Question 5

Describe an enzyme and its function.

An enzyme is a protein that enables other
molecules to undergo chemical changes to
form new products
 Enzymes increase the speed of reactions
that would otherwise proceed too slowly
Video 4
Enzymatic Reactions

Click the image to play the video segment.
Figure 2-19 Chemical Reactions
Section 2-4
Energy-Absorbing Reaction
Energy-Releasing Reaction
Activation
energy
Products
Activation energy
Reactants
Reactants
Products
Figure 2-19 Chemical Reactions
Section 2-4
Energy-Absorbing Reaction
Energy-Releasing Reaction
Activation
energy
Products
Activation energy
Reactants
Reactants
Products
Effect of Enzymes
Reaction pathway
without enzyme
Activation energy
without enzyme
Reactants
Reaction pathway
with enzyme
Activation
energy
with enzyme
Products