biochemistry

1. BIOCHEMISTRY…
The Chemistry of Life

2. FREE WRITE FRIDAY
 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?

3. Bio-Chemistry
 What do you think of when you see the word
Biochemistry?
 List the first 5 things that you think of in your
notebook.

4. Bio Chemistry
 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.

5. I can…
 Identify the parts of an atom AND understand
how atoms interact

6. Matter…
 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

7. Elements…
 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
 Only about 25 different elements are found in
organisms
 However, atoms of different elements can “link” or
bond together to form compounds

8. Isotope
 Elements can have a different number of
neutrons.
 This is called an isotope
 Carbon 14, Carbon 13, and Carbon 12

9. Compounds…
 Atoms form compounds in two ways
1. Ionic bonds – consists of ions and forms
through the electrical force between oppositely
charged ions
 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
2. Covalent bonds – forms when atoms share one
or more pairs of electrons
 A molecule consists of two or more atoms held
together by covalent bonds

10. Why elements bond the way
they do…
 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

11. Try These…
 Identify the type of bond…
1. MgF2
2. S3O2
3. RbCl
4. PCl4
5. N2O

12. Bell Ringer…
1. How is an atom different from a compound?
2. What does the number of protons tell us
about an element?
3. Identify the following as ionic or covalent
compounds
a. Cl2F4
b. CuF2
c. AlBr3
d. CO2
4. Compare and contrast ionic and covalent
bonds

13. 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

14. Bell Ringer…
 Which Property of water is responsible for the
following:
1. Homeostasis
2. Water beading up
3. An iceberg floating in the ocean
4. Water moving against gravity in a flower stem

15. Bell Ringer…
 What makes water so unique?
 Why is water considered a polar molecule?
 What is a hydrogen bond?

16. Carbon based molecules
 Carbon based molecules are the foundation
for life
 Many of these molecules are large and called
polymers. Poly- many
 A repeating unit of the same small molecule
(monomer)
 There are four main types of carbon-based
molecules in living things
1. Carbohydrates
2. Proteins
3. Lipids

17. Bell Ringer…
 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?

18. After Presentation Review…
1. Another name that lipids may be called?
2. Why are nucleic acids so important to living
organisms?
3. List three foods you may find carbohydrates
4. There is a special class of proteins called
enzymes – what is their purpose and why are
they important?

19. Bell Ringer…
1. An athlete is preparing for a triathlon – what
type of food should he eat before hand and
why?
2. 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?
3. Of the four carbon based molecules we
talked about – which two rely on each other
more so than any other?

20. Carbohydrates…
 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

21. Why carbs are important to
living organisms…
 Short-term storage energy storage
 Plant cell wall components – strength
 Component of cell membranes – glycogen
 It helps identify the type of cell

22. Proteins…
 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

23. Why proteins are important to
living organism…
 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

24. Lipids…
 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 fatty acids
 Has at least one carbon = carbon (joined by double
bonds)
 3 fatty acids + 1 glycerol = triglyceride

25. Why lipids are important to
living organisms…
 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

26. Nucleic Acids…
 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)

27. Why nucleic acids are important
to living things…
 DNA
 Blueprint for life
 Our genes
 RNA
 Translates DNA to make PROTEINS

28. Chemical Reactions in the
body…
 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

29. Enzymes…
 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

30. Shapes of enzymes…
 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

31. Bell Ringer…
 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”?

32. How it actually works…
 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

33. One more thing about chemical
reactions and enzymes…
 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
 Endothermic reactions
 Absorbs energy
 Energy in the reactant bonds are lower than in the

34. Important Properties of Water…
 Hydrogen bonds are responsible for several
important properties of water
1. High specific heat – water resists changes in
temperature – it must absorb a large amount of
heat energy to increase the temperature
2. Cohesion – the attraction among molecules of a
substance – makes water “stick” together
 Surface tension
3. Adhesion – the attraction among molecules of
DIFFERENT substances – makes water “stick”
to other materials
 Capillary action

35. Important Properties of Water…
 Hydrogen bonds are responsible for several
important properties of water
4. Expands when freezes – when water freezes its
volume becomes larger than in the liquid or gas
state (just the opposite of most other
compounds)
 Weathering and aquatic organisms

36. 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

37. A little more on water…
 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)

38. Acids and bases…
 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
 Organisms must maintain a staple pH and
even a small change in pH can disrupt many
biological processes (remember
homeostasis?)

39. pH scale…
 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)