Transcript Bio Boot Camp

Bio Boot Camp
Biochemistry:
TOPIC 1
Bio A.2 The Chemical Basis for Life
• Describe how the unique properties of
water support life on Earth (freezing
point, high specific heat, cohesion)
• Describe and interpret relationships
between structure and function at various
levels of biochemical organization (atoms,
molecules, macromolecules)
– Explain how C is uniquely suited to form
biological macromolecules
– Describe how macromolecules form from
monomers
– Compare the structure and function of carbs,
lipids, proteins and nucleic acids
Bio A.2 The Chemical Basis for Life
• Explain how enzymes regulate
biochemical reactions within a cell
– Describe the role of an enzyme as a
catalyst in regulating a specific
biochemical reaction
– Explain how factors such as pH, temp,
and concentration can affect enzyme
function
Properties of Water
1. Is a polar covalent molecule
2. Is the universal solvent due to
its polarity. Polar covalent
compounds (like glucose) and
ionic compounds (like salt) can
easily go into solution in water.
3. Has a high specific heat. It is
slow to heat up and also slow to
cool down. This acts as an
insulator in living organisms
since the majority of their living
tissue is water.
4. When water freezes, it
expands and therefore floats.
Ice is less dense than water.
This provides an insulation to
the organisms in the water. The
water below will be at 4`C (if
ice is above it)
Water – Unique Properties
• Adhesion: Water sticks to
other substances
• Cohesion: water sticks to water
• Capillary actions: Water climbs
up.
– Ex. Plant roots to 400 feet
up.
• Surface Tension: Water
spiders can walk on water.
Water sticks together so
tightly, causes a tension so
certain things can “float”
Water
• The cohesive forces between
liquid molecules are responsible
for the phenomenon known as
surface tension. The molecules
at the surface do not have
other like molecules on all sides
of them and consequently they
cohere more strongly to those
directly associated with them
on the surface. This forms a
surface "film" which makes it
more difficult to move an
object through the surface
than to move it when it is
completely submersed.
Facts about water
• Water resists changes to temperature.
• Water expands when it freezes
• Water is less dense as a solid oppose to
a liquid. Ice floats
• High Specific Heat: able to absorb a lot
of heat before it gets hot
• Universal Solvent
Inorganic
• Water is an inorganic molecule: chemical
compounds that do not contain carbon
as the principle element (exception CO2)
Chemistry of Life
• Organic molecules: molecules that
contain carbon atoms and H atoms
• C atoms are versatile building blocks
– 4 stable covalent bonds (4 valence e-)
– C atoms can bond other C atoms or other
atoms
H
H
C
H
H
Carbon
• Atomic number of 6.
– 2 electrons in the 1st orbital and
4 remaining in the valance orbital.
– 4 unpaired will form 4 covalent
bonds
• By bonding with other carbons
in chains, rings, single, double
and triple bonds, carbon, it can
make all sorts of molecules
Covalent bond –electrons are
SHARED
Carbon double bond
Carbon (and nitrogen) triple bond
Carbon Chains
Branched chain
Carbon rings
Carbon variety
Monomer and Polymer
Monomers are like legos…
• You can put them
together in
whatever way you
dream up!
Macromolecules
• Smaller organic molecules join together
by covalent bonds to form larger
molecules
– built by linking repeating building blocks in
a chain
• 4 major classes of
macromolecules:
–
–
–
–
carbohydrates
lipids
proteins
nucleic acids
Condensation Reaction (Dehydration
Synthesis – removing water to make)
Carbohydrate (CH20)
Monosaccharide, the monomer
of a carbohydrate
Carbohydrates
• Carbohydrates are composed of C, H, O
carbo - hydr - ate
CH2O
(CH
CC66H
(CH
H12
O66
2O)
12O
2O)
x x
• Building block molecules or monomers =
MONOSACCHARIDES (glucose)
sugar
sugar
sugar
sugar
sugar
sugar
sugar
sugar
Carbohydrate Polymers – monomers
linked together by dehydration
synthesis
Functions of Carbohydrates
• Monosaccharides
– Glucose: quick energy
• Polysaccharides
– starch
• energy storage in plants
– glycogen
• energy storage in animals
– in liver & muscles
– cellulose
• structure in plants
– cell walls
Cellulose
Glycogen use and storage
Lipids
Lipids
inside cell
• Function:
– energy storage
– cell membrane
– insulates body
• think whale blubber!
• Examples
– Fats, Oils, Waxes, and
steroids
outside cell
Molecular Structure of Fat
not a chain (polymer) = just a “big fat molecule”
Cell membrane phospholipids
Protein
Proteins
• Function: worker molecules
– many, many functions
• hormones
– signals from one body system to another
– insulin
• movement
– muscle
• enzymes
– help chemical reactions
Proteins
• Building block = amino acids
amino amino amino amino amino
acid – acid – acid – acid – acid

20 different amino acids
H O
H
| ||
—N—
—C—C—OH
|
H variable
group
Peptide
bond
Nucleic Acid
Nucleic Acids
• Function:
– genetic material DNA and RNA
• stores information
– genes
– blueprint for new cells
• transfers information
DNA
– blueprint for building proteins
– DNA  RNA  protein
proteins
Nucleic Acids
• Building block =
nucleotides
nucleotide – nucleotide – nucleotide – nucleotide

5 different nucleotides


different nitrogen bases
A, T, C, G, U
sugar
phosphate
N base
• This is dehydration synthesis.
– Removing water (dehydration)
– To make (synthesis)
– During this type of reaction, a water molecule is
removed (an –OH from one simple monomer and an –H
from another to form a water molecule.
– This joins two monomers together to form a polymer.
Monomer called Glucose
Glucose + Glucose =
Maltose
Use the diagram below to answer the question.
Chemical Reaction
HO – 1 – 2 – 3 – H + HO – 4 - H
HO – 1 – 2 – 3 – 4 – H + H2O
The diagram shows a reaction that forms a polymer from two
monomers.
What is this type of reaction called?
A.Glycolysis
B.Hydrolysis
C.Photosynthesis
D.Dehydration synthesis
Enzymes
• Enzymes are not changed by the
reaction
– Enzymes are specific, they fit to their
substrates like a lock and key
– used only temporarily then reused
– Provide a site for reaction (active site)
substrate
active site
product
enzyme
Catalyst/Enzyme
• Speeds up chemical reactions by lowering
activation energy
Enzyme
• Fit together like a
LOCK AND KEY
Factors that affect enzyme
activity pH
Factors that affect enzyme
activity Temperature
Factors that affect enzyme
activity  Concentration
Two molecules join together to make a
macromolecule with the removal of water.
This type of reaction is called?
A. Glycolysis
B. Hydrolysis
C. Photosynthesis
D. Dehydration synthesis.
A scientist observed that, when the pH of the environment
surrounding an enzyme is changed the rate the enzyme
catalyzes a reaction greatly decreases. Which statement best
describes how a change in pH can affect an enzyme?
A. A pH change can cause the enzyme to
change its shape
B. A pH change can remove energy
necessary to activate an enzyme
C. A pH change can add new molecules to
the structures of the enzyme
D. A pH change can cause an enzyme to
react with a different substrate.
Substance A is converted to substance B in a
metabolic reaction. Which statement best describes
the role of an enzyme during this reaction?
A. It adjusts the pH of the reaction
medium
B. It provides energy to carry out the
reaction
C. It dissolves substance A in the
reaction medium
D. It speeds up the reaction without
being consumed.
Carbohydrates and proteins are two types of
macromolecules. Which functional
characteristic of proteins distinguished them
from carbohydrates?
A. Large amounts of stored information
B. Ability to catalyze biochemical
reactions
C. Efficient storage of usable chemical
energy
D. Tendency to make cell membranes
hydrophobic
Practice Questions
Practice Questions
Practice Questions
Practice Questions
Practice Questions
Practice Questions
Practice Questions
Practice Questions