Transcript Biochemistry…

BIOCHEMISTRY…
The Chemistry of Life
FREE WRITE FRIDAY
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
IN YOUR NOTEBOOK
Has there ever been a time in your life where all of
the odds were against you? If so what was going on
that made you feel that way?
 How
did it make you feel?
 What were some of the obstacles you had to face?
 Did it affect others around you? Positively or
negatively?
 Are you a better person now because of that struggle?
Bio-Chemistry
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What do you think of when you see the word
Biochemistry?
 List
the first 5 things that you think of in your notebook.
Bio Chemistry
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

Bio= life
Chemistry = how things interact
Biochemistry= the branch of science in which you
study the chemical and physical processes that occur
in an organism.
I can…

Identify the parts of an atom AND understand how
atoms interact
Matter…
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
All matter, whether living or nonliving, is made of the
same type building blocks called atoms
An atom is the smallest basic unit of matter
All atoms have the same basic structure, composed of
three smaller particles
Proton – a positively charged particle in an atom’s nucleus
 Neutron – a neutral (no charge) particle which has about
the same mass as a proton and is also in the nucleus
 Electron – a negatively charged particle found outside the
nucleus. Electrons are much, much smaller than proton and
neutrons

Elements…
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Different types of atoms are called elements, which
cannot be broken down by ordinary chemical means
Which element an atom is depends on the number
of protons in the atom’s nucleus
 For
example… all hydrogen atoms have 1proton and
all oxygen atoms have 8 protons
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Only about 25 different elements are found in
organisms
 However,
atoms of different elements can “link” or
bond together to form compounds
Isotope
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Elements can have a different number of neutrons.
This is called an isotope
 Carbon
14, Carbon 13, and Carbon 12
Compounds…
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Atoms form compounds in two ways
Ionic bonds – consists of ions and forms through the
electrical force between oppositely charged ions
1.

An ion is an atom that has lost or gained electrons


Cation – an ion that loses electrons so becomes positively
charged
Anion – an ion that gains electrons so becomes negatively
charged
Covalent bonds – forms when atoms share one or
more pairs of electrons
2.

A molecule consists of two or more atoms held together by
covalent bonds
Why elements bond the way they
do…
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
All atoms want 8 electrons in their outer most
energy level (shell) This is called the octet rule.
That is why they do what they do
 Ionic
bonds – gain or lose electrons
 Covalent share electrons

How do we identify each type
 Ionic
compound – metal + non-metal
 Covalent compound – non-metal + non-metal
Try These…
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Identify the type of bond…
1.
2.
3.
4.
5.
MgF2
S3O2
RbCl
PCl4
N2O
Bell Ringer…
How is an atom different from a compound?
What does the number of protons tell us about an
element?
Identify the following as ionic or covalent
compounds
1.
2.
3.
a.
b.
c.
d.
4.
Cl2F4
CuF2
AlBr3
CO2
Compare and contrast ionic and covalent bonds
Water’s Unique Properties…



The STRUCUTRE of the water molecule gives water
its unique properties
Water is a polar molecule, which means that it has
a region with a slight negative charge (the oxygen
atom) and a region with a slight positive charge
(the hydrogen atoms)
The oppositely charged regions of water molecules
interact to form hydrogen bonds
 Hydrogen
bond is an attraction between a hydrogen
atom and a negative atom
Bell Ringer…
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Which Property of water is responsible for the
following:
1.
2.
3.
4.
Homeostasis
Water beading up
An iceberg floating in the ocean
Water moving against gravity in a flower stem
Bell Ringer…
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What makes water so unique?
Why is water considered a polar molecule?
What is a hydrogen bond?
Carbon based molecules
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Carbon based molecules are the foundation for life
Many of these molecules are large and called
polymers. Poly- many
A
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repeating unit of the same small molecule (monomer)
There are four main types of carbon-based
molecules in living things
1.
2.
3.
4.
Carbohydrates
Proteins
Lipids
Nucleic acids
Bell Ringer…
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What is the main element in an “organic” molecule?
How are monomers related to polymers?
What are the four main “organic” molecules living
organisms need?
After Presentation Review…
1.
2.
3.
4.
Another name that lipids may be called?
Why are nucleic acids so important to living
organisms?
List three foods you may find carbohydrates
There is a special class of proteins called enzymes
– what is their purpose and why are they
important?
Bell Ringer…
1.
2.
3.
An athlete is preparing for a triathlon – what type
of food should he eat before hand and why?
Many animals hibernate in the winter, to do so,
they eat more food than need in the fall. The
extra calories are stored as fat. Why do these
animals do this?
Of the four carbon based molecules we talked
about – which two rely on each other more so than
any other?
Carbohydrates…
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Known as sugars and starches
 Also

include cellulose and glycogen
Made up of monosaccharides (monomer) which can
be put together to form disaccharides and
polysaccharides
 Disaccharides
– sucrose (table sugar)
 Polysaccharides – starch, cellulose (cell wall
component), and glycogen (storage of carbs in the liver
and muscle)
 Glycogen
is important for insulin in humans
Why carbs are important to living
organisms…
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
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Short-term storage energy storage
Plant cell wall components – strength
Component of cell membranes – glycogen
 It
helps identify the type of cell
Proteins…
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
Known as meat to us
Made up of amino acids (monomer) which can be
put together to form polypeptides (50-300 a.a.)
 20
different amino acids are found in human proteins
Why proteins are important to
living organism…
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Form body tissue
 Skin,

hair, muscles
Important for immune response
 Antibodies

– fight off foreign invaders
All enzymes in the body
 Biological
catalysts – they speed chemical reactions
inside the body
Lipids…
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Known as fats, oils and waxes
Made up of glycerol and fatty acids
 Saturated
fatty acids
 Single
bonds join carbon (carbon – carbon) together
 Are oils at room temperatures
 Unsaturated
 Has

fatty acids
at least one carbon = carbon (joined by double bonds)
3 fatty acids + 1 glycerol = triglyceride
Why lipids are important to living
organisms…
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Long term storage of energy
 Fat

is the storage mechanism
Formation of cell membranes
 Nerves
and brain tissue
 Phospholipids and cholesterol
 Phospholipids

have hydrophobic heads and hydrophilic tails
Hormones
 Made
of steroids
Nucleic Acids…
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
Known as DNA and RNA
Made up of nucleotides
A
nucleotide consists of
 Phosphate
group
 Pentose sugar (5-carbon sugar)
 Nitrogen base (A, T, C, G, or U)
Why nucleic acids are important to
living things…

DNA
 Blueprint
for life
 Our genes
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RNA
 Translates
DNA to make PROTEINS
Chemical Reactions in the body…
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Chemical reactions require the addition of energy,
called activation energy , to take place
Even if a chemical reactions starts, it may not
happen very quickly
However, both the activation energy and the rate of
a chemical reaction can be changed by a catalyst
A
catalyst is a substance that decreases the activation
energy for a reaction and increases the rate of
reaction
 Enzymes
are biological catalysts
Enzymes…
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
Almost all enzymes are proteins and almost every
process in living things needs enzymes
The function of each enzyme depends on its
structure
A
change in biological conditions can affect the shape
of an enzyme, which can decrease or prevent an
enzyme from working properly
 For
example, enzymes function best in a small range around
an organism’s normal temperature and pH
Shapes of enzymes…
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
The shape of an enzyme is important because it
allows only certain molecules to bind to the enzyme
The specific molecules that an enzyme acts on are
called substrates
 It
works like a puzzle or lock and key – only certain
pieces fit together for it to work
 If
an enzymes structure changes, the substrate cannot bind to
the enzyme
Bell Ringer…
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What does the activation energy tell us for a
particular reaction?
How does a catalyst affect a chemical reaction?
Why would enzymes be called a “lock and key” or
“puzzle piece”?
How it actually works…
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Substrates bind to the enzyme
The enzyme brings molecules close together so that
they can react with one another
The bonds inside the substrate are stretched slightly
out of position, which weakens the bonds
The reaction takes place and the product is
released from the enzyme
 Less

energy is needed to break weaker bonds
The enzyme can then bind to more of the substrate
molecules
One more thing about chemical
reactions and enzymes…
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There are two types of energy changes that can
occur with chemical reactions
 enzymes

do not change this for an reaction
Exothermic reactions
 Releases
energy (usually in the form of heat or light)
 Energy in the reactant bonds are higher than in the
product bonds
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Endothermic reactions
 Absorbs
energy
 Energy in the reactant bonds are lower than in the
product bonds
Important Properties of Water…
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Hydrogen bonds are responsible for several
important properties of water
High specific heat – water resists changes in
temperature – it must absorb a large amount of heat
energy to increase the temperature
Cohesion – the attraction among molecules of a
substance – makes water “stick” together
1.
2.

Surface tension
Adhesion – the attraction among molecules of
DIFFERENT substances – makes water “stick” to other
materials
3.

Capillary action
Important Properties of Water…

Hydrogen bonds are responsible for several
important properties of water
Expands when freezes – when water freezes its
volume becomes larger than in the liquid or gas state
(just the opposite of most other compounds)
4.

Weathering and aquatic organisms
Lab Requirements…

All Labs must have the following UNLESS changed
by me…
 Title
and Date
 Purpose
 Pre-Lab Questions (if any)
 Procedure (max of 3 sentences)
 Data
 Post Lab Questions (must be in complete sentences)
 Conclusions
A little more on water…
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Many compounds that are important for life dissolve
in water.
Water is the largest component of cells’ interiors,
and chemical reactions in the cell take place in
water
When one substance dissolves in another – a
solution is made
 Each
solution is made up of two parts
 Solute
– what gets dissolved (usually in smallest amount)
 Solvent – what does the dissolving (usually in the largest
amt)
Acids and bases…
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When some substances dissolve in water they break
up into ions
Acids and bases are such substances – they are
very important to living organism
 Acids
– release H+ ions when dissolved in water
 Bases – accept H+ ion when dissolved in water
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Organisms must maintain a staple pH and even a
small change in pH can disrupt many biological
processes (remember homeostasis?)
pH scale…
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The pH scale runs from 0 to 14
O – 6 are considered acids (low pHs)
7 is neutral
8 – 14 are considered bases (high pHs)