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Biochemistry
Part 1: Macromolecules
Macromolecules
Macro means “large”.
Macromolecules are huge molecules
made from long chains of smaller units.
There are four major types of
macromolecules in the human body:
carbohydrates
fats (lipids)
proteins
nucleic acids
Macromolecules
While each type of macromolecule is different,
they have one major thing in common:
Macromolecules are made of long
chains called polymers (poly = “many”)
Polymers are made up of smaller subunits
called monomers (mono = “one”)
Let’s look at an example…
Monomer vs. Polymer
Take a pearl necklace, for example:
Polymer
Monomer
Made up of many
pearls in a chain
Each pearl is a
separate unit
G
G
G
G
G
G
G
G
glucose
carbohydrates
amino acids
proteins
glycerol + fatty acids
lipids
phosphate + ribose
nucleic acids
G
Carbohydrates
Carbohydrates are made from glucose.
Glucose can be combined in different
ways to make 3 types of carbohydrates:
starch
glycogen
cellulose
Starch is a branched chain of glucose used in plants
G
G
For storing
energy
G
G
G
G
G
G
G
Glycogen is a branched chain used in animals
G
G
G
For storing
energy
G
G
G
G
G
G
Cellulose is a long chain of glucose used in plants
G
G
For
building
G
G
G
G
G
G
G
G
G
G
G
G
G
G
G
Carbohydrates
Clusters Starch
of glycogen
(black
dots)
in a
liver cell.
Cellulose
granules
fibres
inside
in plant
paper
cells.
Lipids
Fats are only one type of lipid.
Lipids are made up of fatty acid molecules
bonded to a glycerol molecule.
There are 4 main types of
lipids in living things:
fats / oils
phospholipids
cholesterol
hormones
Fats vs. Oils
Fats and oils are very similar.
Fats are usually solid at room temperature.
Fats have fatty acid chains closely packed.
saturated fat
Fats vs. Oils
Fats and oils are very similar.
Oils are usually liquid at room temperature.
Oils have fatty acid chains loosely packed.
unsaturated fat (oil)
Phosholipids
Phospholipids make up cell membranes.
Phospholipids combine together to make
a twin layer (bilayer) that is waterproof.
The Cell Membrane
Proteins
Proteins are made from smaller amino acids.
There are 20 different amino acids, which
can combine in a huge number of ways.
Proteins have a huge
number of uses:
structure
defense
digestion
energy
Protein Structure
Nucleic Acids
Nucleic acids make up our DNA.
Nucleic acids are made of ribose (a sugar),
a phosphate group and a nucleotide.
There are 4 different
nucleotides in DNA:
adenine
guanine
cytosine
thymine
Nucleic Acids
Nucleic acids make up our DNA.
Nucleic acids are made of ribose (a sugar),
a phosphate group and a nucleotide.
There are 4 different
nucleotides in DNA:
adenine
guanine
cytosine
thymine
A
C
G
T
Nucleotide Pairing
The nucleotides pair up in a certain way.
Adenine always pairs with Thymine
A
T
Cytosine always pairs with Guanine
G
C
Nucleotide Pairing
The nucleotides pair up in a certain way.
Adenine always pairs with Thymine
A
T
All Tigers Can Growl
Cytosine always pairs with Guanine
G
C
Nucleic Acids
A Review
carbohydrates
proteins
Made from glucose
e.g. starch, glycogen,
and cellulose
Made of amino acids
e.g. keratin, muscle,
collagen, enzymes
energy, structures
wide range of uses
lipids
nucleic acids
Made of glycerol
+ fatty acids
e.g. fats, oils, steroids
Make up of ribose
+ 4 nucleotides
e.g. adenine, guanine
energy, structures
storing information
Any Questions?
Biochemistry
Part 2: Photosynthesis
Glucose
Leaves make food for the plant.
The food that a plant uses is a
macromolecule called glucose.
Glucose is a hexagon-shaped
molecule made up of carbon,
hydrogen and oxygen.
Glucose stores chemical
energy in its chemical bonds.
Photosynthesis
Leaves make glucose from sunlight.
Plants produce glucose through a
chemical reaction called photosynthesis.
PHOTO SYNTHESIS
“with light” “making”
Photosynthesis occurs mainly in the leaves of plants.
Photosynthesis
Leaves make glucose from sunlight.
Plants produce glucose through a
chemical reaction called photosynthesis.
PHOTOSYNTHESIS
“making with light”
Photosynthesis occurs mainly in the leaves of plants.
Chloroplasts
Photosynthesis take place in cells with chloroplasts.
Chloroplasts are organelles that capture
light energy and use it to make glucose.
Chloroplasts contain a green
pigment called chlorophyll.
Chlorophyll absorbs light
energy to create glucose.
Chloroplasts
Raw Materials
Energy
from sun
O2
to air
CO2
Chlorophyll
from air
chloroplasts
H 2O
from soil
C6H12O6
to plant
The Reaction
The word and chemical equation for photosynthesis:
Sunlight
Carbon
Dioxide
+
Water
>
Glucose
+
Oxygen
CO2
+
H 2O
>
C6H12O6
+
O2
Chlorophyll
Chemical Equation
The chemical equation for photosynthesis is:
6CO2 + 6H2O
Light Energy
Chlorophyll
C6H12O6 + 6O2
Using Glucose
Glucose has several uses in the plant.
1. Glucose is burned in mitochondria for energy
e
e
G
G
2. Glucose is stored as larger starch molecules
G
G
G
G
G
G
G
G
G
3. Glucose is turned into cellulose to build things
G
G
G
G
G
G
G
G
G
G
G
G
G
G
G
G
G
4. Glucose is turned into proteins to build things
G
G
5. Glucose is turned to fats and stored in seeds
G
G
G
Leaf Anatomy
Leaves are adapted to perform photosynthesis.
green
coloring
broad and
flat shape
chlorophyll
traps sunlight
To collect
sunlight easily
waxy
covering
veins and
stem
Waterproofs
the leaf on top
To carry water
from the roots
Leaf Anatomy
Leaves are adapted to perform photosynthesis.
cuticle
upper
epidermis
spongy
cells
palisade
cells
air spaces
vein
stomata
lower
epidermis
Leaf Anatomy
cuticle
upper
epidermis
spongy
cells
palisade
cells
air spaces
stomata
lower
epidermis
Stomata
Leaves have tiny pores on the bottom.
These holes are called stomata (pl).
Singular: one stoma
Stomata allow gases to
enter and exit the leaf
CO2 enters
O2 exits
H2O vapor exits
Stomata
Stomata can be opened or closed.
Stomata are surrounded by sausage-shaped
guard cells that control its opening/closing .
When guard cells swell up
with water, the stomata opens.
When guard cells lose water,
the stomata closes.
Stomata
Stomata
Limiting Factors
Photosynthesis is a chemical reaction.
Since it is a chemical reaction, it
can be sped up or slowed down.
The rate of the reaction depends on 3 factors:
Light Levels
CO2 Levels
Temperature
They are called limiting factors because if any ONE
of them is in short supply, it will limit the rate of P/S.
Light Levels
P/S ↑ as light levels ↑
…but it will then be limited
by CO2 or temperature
CO2 Levels
P/S ↑ as CO2 levels ↑
…but it will then be limited
by light or temperature
Temperature
P/S ↑ as temperature ↑
…but soon the enzymes in
P/S are destroyed by heat
IMPORTANT!
Plants go through respiration, just like humans do!
1. Glucose is burned in mitochondria for energy
The difference between plants and us is that
G
plants make their own food through
P/S e!
e
G
During the day, plants take in CO2 and H2O
to produce C6H12O6 and release O2 as waste.
But at night, plants take in O2 and burn
C6H12O6 to produce CO2 and H2O as waste.
Any Questions?
Biochemistry
Part 3: Cellular Respiration
Like A Fire?
In order for a fire to burn, it needs TWO things:
Fuel
Oxygen
A fire combines these 2 things in a
chemical reaction that releases energy
Our bodies are NO different!
Energy For Life
All cells require energy to survive.
Glucose is the main source of energy.
Cells release energy in three different ways:
Aerobic Respiration
Anaerobic Respiration
Fermentation
Aerobic Respiration
Aerobic means “with oxygen”.
In aerobic respiration, cells use oxygen
to release the energy stored in glucose.
Aerobic respiration takes place in
organelles called mitochondria.
The mitochondria absorb
glucose and oxygen from the blood
and produce energy for the cell.
Aerobic Respiration
The word equation for aerobic respiration is:
Brought
to cells
by the
blood
Inhaled
by lungs
Carried
by blood
Carried
by blood
Carried
by blood
Exhaled
by lungs
Lost as
sweat, etc.
Used
for all
body
actions
Aerobic Respiration
The word equation for aerobic respiration is:
The chemical equation is:
Aerobic Respiration Facts:
It is used for non-strenuous activities.
It supplies daily energy for the body
in slow and steady amounts.
It is a very efficient reaction.
One glucose molecule makes 20x
more energy than anaerobic respiration.
It is a relatively safe reaction.
It produces no negative side effects.
Anaerobic Respiration
Sometimes, energy is needed much quicker!
Anaerobic respiration releases small
amounts of energy without oxygen.
This reaction is also called fermentation.
There are two types of fermentation:
Anaerobic Respiration
In muscle cells
Alcoholic Fermentation
In yeast cells
Anaerobic Respiration
The word equation for anaerobic respiration is:
Brought
to cells
by the
blood
Builds up
in muscles
Makes them
fatigue & ache
Energy
released
very
quickly
Anaerobic Respiration
The word equation for lactic acid fermentation is:
The chemical equation is:
Why Use Fermentation?
Anaerobic respiration is a harmful process.
It releases lactic acid as a waste,
causing muscles to fatigue and cramp.
It is only used when the
muscles work very hard.
When this happens, the heart
cannot deliver oxygen and glucose
fast enough for aerobic respiration.
Anaerobic Respiration Facts
It produces energy almost instantly.
It is only used for high intensity activities
for a short time (sprinting, climbing).
It is an inefficient reaction.
One glucose molecule makes 1/20th the
amount of energy as aerobic respiration.
It can only last for a short time.
Lactic acid build up will damage muscles.
Alcoholic Fermentation
Other organisms create energy differently.
Alcoholic fermentation breaks down
glucose into alcohol & carbon dioxide.
Remember, it occurs without oxygen!
Yeast cells can use alcoholic
fermentation to produce energy
if they are deprived of oxygen.
Yeast Cells
Alcoholic Fermentation
The word equation for alcoholic fermentation is:
Fed to the
yeast cells
Used to
make
alcoholic
beverages
Used to
make
dough rise
Used
by the
yeast cells
Fermented Food
Alcoholic fermentation produces useful products:
Alcohol can be used to make:
Carbon dioxide can be used to make:
Fermented Food
Some bacteria use anaerobic respiration to
make energy, the lactic acid can be used in food.
Lactic acid hardens milk to produce:
A Summary
Aerobic Respiration – with oxygen
C6H12O6 + 6O2 à 6CO2 + 6H2O + 32 ATP
Anaerobic Respiration – without oxygen
C6H12O6 à 2 C3H6O3 + 2 ATP
Alcoholic Fermentation – without oxygen
C6H12O6 à Alcohol + CO2 + Some Energy
Any Questions?