Transcript nucleic acids - Cloudfront.net

Chapter 2
THE CHEMISTRY OF
LIFE
California State Standards



1h: most macromolecules in cells and organisms are
synthesized from a small collection of simple
precursor
4e: proteins can differ from one another in the
number and sequence of amino acids
1b: enzymes are proteins that catalyze biochemical
reactions without altering the reactions equilibrium
and the activities of enzymes depend on the
temperature, ionic conditions, and the pH of the
surroundings
CHAPTER 2: THE CHEMISTRY OF LIFE
The first job of a biologist is to understand the chemistry of life.
2-1 The Nature of Matter
A. Atoms
Atoms
 ___________=
the basic unit of matter (has
volume and mass; solid, liquid, gas,
and plasma)
 Atoms are made
subatomic particles called protons,
neutrons, and electrons
Carbon Atom
=
-
= protons
- Positively charged
- 1 amu
= neutrons
- No charge
- 1 amu
-
electrons
Electronegative charge
1/1840 amu
electrons travel in
regions outside the
nucleus called orbitals
Nucleus
_______________=
center of an atom.
Home to protons
and neutrons.
B
B. Elements
 Elements= pure substances that consists entirely of one
type of atom
100
 More than _____known
kinds; 2 dozen are
common in living organisms
 Found on the Periodic table
Reading the Periodic Table
Example: The element Carbon (only made of carbon atoms)
An Element in the Periodic Table
Atomic number =
Number of protons
in an atom; different
for each element
Section 2-1
SYMBOL
____________
usually 1-2
letters
_______________=
MASS NUMBER
# Protons + #
neutrons in an atom;
the average of one
elements isotopes
6
C
Carbon
12.011
____________
NAME
of the element
Isotopes are the various forms of an
atom that differ based on the
number of neutrons in the nucleus
such as C 14. The isotopes that
differ from the most common form
are often radioactive or unstable.
C. Chemical Compounds
1. Chemical compound= a substance formed by the
combination of 2 or more
elements in definite
proportions.
Example: Sodium Chloride = Table salt Forms when
sodium and chlorine combine in a 1:1 ratio
2. Chemical formula= a short hand that shows
chemical composition
Example: Sodium Chloride= NaCl
Chemical properties
3. ____________________________
of a molecule
Example:
NaCl = white crystalline solid
Na = a soft silvery metal that reacts
explosively with water
Cl = poisonous greenish gas
D. Chemical Bonds
•
Atoms in compounds are held together by links called
chemical bonds.
•
Involves the interaction of electrons
•
covalent and _________
ionic
2 main types of bonds are: ___________
1. Ionic Bonds
a. are formed by the transfer of one or more
electrons from one atom to
another.
b. ion= an atom that has a positive or
negative charge as a result of
gaining or losing electrons.
FORMING AN IONIC BOND
Figure 2 -3 Ionic Bonding
Section 2 -1
Sodium atom (Na)
Chlorine atom (Cl)
Sodium ion (Na +)
Chloride ion (Cl -)
Transfer
of electron
Protons +11
Electrons -11
Charge
Protons +17
Electrons -17
Charge
0
0
Protons +11
Electrons -10
Charge
+1
c. Opposite charges attract creating a bond between the ions
Protons +17
Electrons -18
Charge
-1
2. Covalent Bonds
a. formed by the sharing of electrons between 2
atoms.
b. Sharing means that the moving electrons are
actually traveling in the orbitals of both
atoms.
c. atoms sharing 2 electrons= single bond
__
4 electrons=double bond
6 electrons= triple bond
d. _________________=
The smallest unit of
Molecule
most chemical compounds
(those joined with covalent bonds)
2-2
What property of water explains
why this insect can stand on water?
Why does ice float?
Ice is less dense than water.
Solid (Ice)
Liquid (water)
Gas (water vapor)
Water is Polar—uneven distribution
of electrons
Hydrogen bonds
Water Cohesion & Adhesion
Water properties
http://www.uni.edu/~iowawet/H2OProperties.html
http://www.ccs.k12.in.us/chsBS/kons/kons/physical_properties_of_water.htm
Solution
Water has a pH of 7 which means that [H+] = [OH-]
Acids contain higher concentrations of [H+] ions than water.
Bases contain lower concentrations of [H+] ions than water.
2-2 Properties of Water- Refer to reader’s guide
2-3 Carbon Compounds
A. The Chemistry of Carbon
valence electrons which means
1. Carbon has 4
________________
covalent bonds.
carbon can form 4
_________________
2. Living organisms are made up of molecules
that consist of carbon, hydrogen, oxygen,
phosphorus, nitrogen and sulfur.
3. Carbon can bond with itself forming chains of
unlimited
and form,
rings, and complex
Figurelength
2-11 Carbon
Compounds
structures.
Section 2-3
Methane
Acetylene
Butadiene
Benzene
Isooctane
B. Macromolecules
1. Macromolecules= are giant molecules consisting
of 1000+ smaller molecules.
2. Polymerization= process of joining small molecules to
form large molecules
3. Monomers= small units that form polymers (large
molecules)
4.  The _____
4 groups of organic compounds
found in living things are:
• carbohydrates
• lipids
• nucleic acids
• proteins
Polymerization
http://www.uwsp.edu/chemistry/tzamis/additionpolymer.html
Made
of
Carbohydrate
C,H,O
1:2:1
Example
Glucose
C6H12O6
Function
1.Stores Energy
-animals =
GLYCOGEN
Monomer
Monosaccharide =
SINGLE SUGAR
-plants =
STARCH
Mono + mono
2. Structural
+mono=
Purposes
- PLANT CELL POLYSACCHARIDE
WALLS
(CELLULOSE)
- CHITIN (INSECT
EXOSKELETON)
Lipids
Mostly
C, H
Very
little
O
1.
FATS
OILS
WAXES
2.
STEROIDS
Stores
Energy
Form cell
membranes
3. Waterproof
coverings
4. Chemical
messengers
1 glycerol
3 fatty acids
SaturatedNO DOUBLE
BONDS IN FATTY
ACID
UnsaturatedAT LEAST
ONE DOUBLE
BOND
Challenge Question
Why are most unsaturated fats liquid at room temperature?
• Unsaturated
Made
of
Nucleic
acids
C
H
O
P
N
Example
Function
DNA/RNA Stores and
transmits
hereditary
information
Monomer
Nucleotide=
1. 5-C SUGAR
2. PHOSPHATE
GROUP
3. NITROGENOUS
BASE
Proteins C
H
O
N
methionine
Shape
determines
function
1.HELPS
CONTROL
RATE OF
REACTIONS
(ENZYMES)
2. pump small
molecules in and
out of the cell
3. aids in cell
movement
Amino acids
20 KINDS
Carbohydrates
Lipids
Nucleic acids
• Nucleic acids are
polymers of nucleotides
joined together to make
large macromolecules.
• The important nucleic
acids are
deoxyribonucleic
acid(DNA) and various
types of ribonucleic
acids(RNA).
Proteins
• Protein are the
building blocks of our
body. We find protein
in our bones, and
muscles. We find
protein in our hair and
nails. There is protein
in our brain, and also
protein is part of our
blood.
Summary
http://www.chemistryland.com/ElementarySchool/BuildingBlocks/BuildingOrganic.htm
Concept Summary
Concept Map
Choose from the following: lipids, nucleotides, amino acids, fats and oils,
Carbohydreat
sugars and starches, carbohydrates, nucleic acids, proteins
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
Carbon,
hydrogen,
oxygen
Carbon,
hydrogen,
oxygen
which contain
which contain
Carbon,hydrogen,
oxygen, nitrogen,
phosphorus
Carbon,
hydrogen,oxygen,
nitrogen,
IQ Quiz: Chapter 2
1.
2.
3.
4.
What kind of compounds did we test in the lab?
What chemical was used to test for simple sugars?
What was a positive result?
If we want to see if peanuts have fat in them what
could we do?
5. How do we know if it is positive?
6. What did copper sulfate and sodium hydroxide test
for?
7. What was a positive result?
8. If I had a bowl of cereal and Iodine fell into my cereal
and turned a blue-black color what do I know is in my
cereal?
9. Name a food that had more than 1 compound in it?
(tested positive for more than 1 test)
10. What are the four most common elements in living
things?
2-4 Chemical Reactions and Enzymes
A. Chemical Reactions =process that changes, or
transforms one set of chemicals into
another. Always involves changes in
chemical bonds.
1. Reactants= elements or compounds that enter a
reaction
2. Products= elements or
compounds produced
by a reaction
EXAMPLE:
HCl
H + Cl
B. Energy in Reactions
• Activation Energy=
energy that is needed to get a reaction started
C. Enzymes
1. Catalyst= a substance that speeds up
the rate of a chemical
reaction without changing
itself.
2. Catalysts ___________________________in
a chemical reaction.
lower the activation energy
Reaction with no enzyme
AE without enzyme
AE with enzyme
reactants
Reaction with an enzyme
products
3. ______________
are ___________________
Enzymes
biological catalysts that
speed up favorable (spontaneous) reactions.
speed up chemical reactions that
4. Enzymes _____________
take place in cells.
5. Enzymes are very specific
D. Enzyme Action
1. The Enzyme-Substrate Complex
a. Enzymes provide a site where reactants can be
brought together to react (increasing the rate of reaction
by reducing the activation energy)
Figure 2 -21 Enzyme Action
Enzyme Activity
Section 2 -4
Active site=
Site on the enzyme where
the substrate attaches
Enzyme
(hexokinase)
Glucose
Substrates
Products
ADP
Glucose -6phosphate
ATP
Products
are released
The
reactants
of a
catalyzed
reaction
Substrates
bind to
enzyme
Substrates
are converted
into products
Enzymesubstrate
complex
b. Enzymes are not consumed in the reaction; after
products are formed, the enzyme is recycled.
2. Regulation of Enzyme Activity
- Enzyme activity depends on environmental
factors such as:
 pH
(enzymes in the stomach function best around
pH=2)
 temperature
(human enzymes function best around 37°C)
-Ionic conditions (coenzymes)
-Substrate concentration (greater
the concentration the greater the
rate of the reaction)
http://www.kscience.co.uk/animations/model.swf
http://www.lewport.wnyric.org/JWANAMAKER/animations/Enzyme%20activity.html
Warm-up questions
1.
Describe the difference between
ionic and covalent bonds. Provide
an example for each.
Warm-up
1. What are the 4 organic
macromolecules which make up
living organisms.
2. What are the monomers (building
blocks) to these macromolecules.
Warm-up
1. What is a catalyst?
2. What are enzymes?
3. How do catalyst work?
4. What affects the activity of an
enzyme?
Review
1.
The positively charged particle in
an atom is the
a.
Neutron
Ion
Proton
electron
b.
c.
d.
Review
2.
a.
b.
c.
d.
Two or more different atoms are
combined in definite proportions in
any
Symbol
Isotope
Element
Compound
Review
3.
A covalent bond is formed by the
a.
Transfer of electrons
Sharing of electrons
Gaining of electrons
Losing of electrons
b.
c.
d.
Review
4.
When you shake sugar and sand
together in a test tube, you cause
them to form a
a.
Compound
Mixture
Solution
suspension
b.
c.
d.
Review
5.
A compound that produces
hydrogen ions in solution is
a.
Salt
Acid
Base
polymer
b.
c.
d.
Review
6.
In polymerization, complex
molecules are formed by the
joining together of
a.
Macromolecules
Carbohydrates
Polymers
monomers
b.
c.
d.
Review
8.
Proteins are polymers formed from
a.
Lipids
Carbohydrates
Amino acids
Nucleic acids
b.
c.
d.
Review
9. An enzyme speeds up a reaction by
a.
b.
c.
d.
Lowering activation energy
Raising activation energy
Releasing energy
Absorbing energy
Review
10.
In a chemical reaction, a reactant
binds to an enzyme at a region
known as the
a.
Catalyst
Product
Substrate
Active site
b.
c.
d.
Standardized Test Prep
1.
2.
3.
An attraction
between different
substances
Lower a chemical
reaction’s
activation energy
The elements or
compounds that
enter into a
chemical reaction
Choose:
 Cohesion
 Adhesion
 Catalysts
 Reactants
 Products
STP
4.
a.
b.
c.
d.
e.
Which one of the following is NOT
an organic molecule found in living
organisms
Protein
Nucleic acid
Carbohydrate
Sodium chloride
lipid
STP
5.
a.
b.
c.
d.
e.
Which combination of particle and
charge is correct?
Proton: +
Electron: +
Neutron: Proton: Electron: 0
STP
6.
In which of the following ways do
isotopes of the same element differ?
a.
# neutrons only
#protons only
#neutrons and protons
#protons and mass
#neutrons and mass
b.
c.
d.
e.
STP
7.
a.
b.
c.
d.
e.
Which of the following molecules is
made up of glycerol and fatty
acids?
Sugars
Starches
Lipids
Nucleic acids
Proteins
STP
8.
Nucleotides consist of a phosphate
group, a nitrogenous base, and a
a.
Fatty acid
Starch
Lipid
5 carbon sugar
6 carbon sugar
b.
c.
d.
e.