Transcript Chapter 2 – Discovering Life

Chapter 6
Biochemistry
Basic Chemistry

Living things are made
up of matter & all matter
is composed of atoms
Composition of Matter


Matter is anything that
has mass and takes up
space
All organisms are
composed of matter
Composition of Matter


Elements are made of
atoms
Elements bond to make
compounds
Atom


An atom is the basic unit of
matter.
They are composed of
subatomic particles
–
–
–
Protons (+)
Neutons (0)
Electrons (-)
Atoms


Horizontal rows are called periods.
Vertical columns are called groups.
Hydrogen
1




1.008
Hydrogen (element
name)
Atomic Number (equal
to the # of protons or #
of electrons)
Element Symbol
Atomic Mass (equal to
the number of protons,
neutrons & electrons in
a single atom)
Ions


An ions is an atom that has
gained or lost electrons.
Anions gain electrons
–

(ex. Cl-)
Cations lose electrons
–
(ex. Na+)
Chemical Bonds

Force that holds two or
more ions or atoms
together
Bond
–
Single, double, or
triple bonds
Ionic Bonds
 Ionic
bonds form between
ions (ex. salt  NaCl)
–
Metal + Nonmetal
Sodium Chloride – NaCl – Table
Salt
Covalent Bonds
 Covalent
bonds form
between two nonmetals.
(ex. Water  H2O
–
–
Nonmetal + Nonmetal
Forms when electrons
are shared
van der Waals Forces
 Attractive
forces between
oppositely charged regions of
molecules.
Geckos Climbing Glass
Surface:
 Attributed
to Van der Waal
forces
 Between surface
and microscopic
projections on
their feet!
Molecules of Life
You Are
What
You Eat
“You Are What You Eat”
Nutrition
Facts label
– a summary of our
basic biochemistry
– Why do we need to eat
these?
Organic Molecules



Contain carbon
Molecules join to form
Macromolecules: large
molecules
Held together with
covalent bonds
Macromolecules are Polymers
Polymers
are molecules
held together by
covalent bonds
 Made of monomers
Four classes of
macromolecules
Carbohydrates
Lipids
Proteins
Nucleic
Acids
Carbohydrates



Provide energy to cells
Subunit =
glucose
Contain carbon,
hydrogen
and oxygen.
Types of Carbohydrates
1. Simple
carbohydrates
 mono- & di-saccharides
2. Complex carbohydrates
 Starch, glycogen, and
cellulose
 Known as polysaccharides
Simple Carbohydrates
 Easy
to digest
 Monosaccharide Examples:
– Glucose: simple sugar
– Fructose: fruit sugar
– Lactose: milk sugar
Monosaccharide’s:
 Glucose
 Fructose (isomer of glucose)
 Galactose (isomer of glucose)
 Ribose
 Deoxyribose
Isomers:
 Same
chemical formula but
different arrangement of
elements:
Glucose
Galactose
Disaccharides:
 Sucrose
- Table sugar
 Lactose - Milk sugar
 Maltose - Malt sugar
Making Disaccharides:
 Sucrose
= glucose + fructose
 Lactose = glucose +
galactose
 maltose = glucose + glucose
How to build a
disaccharide:

Done through a process called
dehydration synthesis

A.k.a. Dehydration reaction

Water (H2O) is lost
http://nhscience.lonestar.edu/biol/dehydrat/dehydrat.html
How to break down a
disaccharide:
 You
break down a disaccharide
or a polysaccharide by
Hydrolysis
 Water (H2O) is added!
 Disaccharides must be broken
down or digested before
entering the cell.
Complex Carbohydrates
Longer
to digest
Long chains of
monosaccharides
so they are
polysaccharides
Complex Carbohydrates (cont.)
 Starch
 Glycogen:
energy storage
 Cellulose: plant
structure
Starch:
 Long
repeating chains of
monosaccharides.
 It is called cellulosewhen found in
plant tissue (roots and grain)
 It is called glycogen when found
in animal tissues (muscles and
liver)
Glycogen:
 Used
for energy storage
so when the body needs
energy between meals or
during physical activity it
is broken down into
glucose.
Cellulose:
 Provides
structural
support in plant cell walls.
 Becomes fiber when we
eat plants; helps regulate
us!
Discussion Questions:
1. Why should we limit
some simple sugars?
2. Why do athletes eat
complex carbohydrates
before a long run / game?
Proteins



Subunits = amino acids
Amino acids are made up
of C, H, N, O, and
sometimes sulfur.
There are 20 amino acids!
Proteins
Proteins
 Several
covalent bonds
called peptide bonds join
amino acids together to form
proteins.
 Proteins a.k.a. polypeptides

Through what process? How do you
build a polymer?
Proteins
Proteins
differ in:
–#, type & the
arrangement of
amino acids
Protein Function:
 Make
up 15% of your total
body mass
 Affected by the order of the
amino acid chain.
 Typically made up of 100 +
amino acids.
Protein Function:
Chains
combine to
form proteins or
polypeptides!
What do proteins do?
1.
Enzymes: speed up or
Increase rate of chemical
reactions / lowers
activation energy
 Ex. Amylase converts
starch to simple sugar
Rates of Chemical Reaction
Energy
is needed to start
reaction: Activation Energy
Reactants
Products
What affects enzyme function?
pH
Temperature
What do proteins do? (cont.)
Transport: substances
inside the cell and between
cells
Ex. Hemoglobin (red blood
cell protein- carries Oxygen)
2.
What do proteins do?
(cont.)
Defense: Antibodies
which are used to
defend the body from
foreign invaders.
3.
What do proteins do? (cont.)
4. Structure: Collagen, Ligaments,
Tendons are made
up of proteins.
What do proteins do? (cont.)
5. Regulation: can be
Hormones
Ex. Insulin which regulates
glucose levels in the body!
What do proteins do? (cont.)
6.
Motion: muscle protein
which allows you to move!
Lipids



Subunit = Fatty Acids
Insoluble in water but
soluble in oil
Important for
homeostasis
Function of Lipids
1.Energy storage (Fat)
2.Regulate body functions
 Steroids: Cholesterol,
Hormones (testosterone &
estrogen)
Function of Lipids (cont.)
3.
Provide structure:
in cells & waxy
coating on plants
Saturated Fats
Called
triglyceride
Hard & solid at room temp
Ex. Meat, Dairy, Butter,
Chocolate, Animal Fats
Unsaturated Fats
“Kinked”
carbon chain
Liquids at room temp
Ex. Peanuts, Fish, Olive Oil
Saturated v.s. Unsaturated
Trans Fats
Worst
type of fat
Increases risk of
heart problems
Discussion Questions
Which
type of fats
should we eat less of?
– Saturated & trans fats:
linked to heart disease
Discussion Questions
How
many calories must
you burn to lose 1 lb of
fat?
– 3,500 calories!!!
Nucleic Acids
Subunit
=
Nucleotide
Two types
DNA & RNA
DNA
Deoxyribonucleic
Store
genetic
information
Double helix
acid
RNA


Ribonucleic Acid
Helps synthesize
(create) proteins