Chapter 6 Biochemistry
Jan 13, 2016
Chapter 6Biochemistry
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 (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)
Hydrogen
1
1.008
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– Single, double, or
triple bonds
Bond
Ionic BondsIonic 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 You Are What What You EatYou Eat
““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
CarbohydratesLipids ProteinsNucleic 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
GlucoseFructose (isomer of glucose)
Galactose (isomer of glucose) RiboseDeoxyribose
Monosaccharide’s:
Isomers: Same chemical formula but
different arrangement of elements:
GlucoseGalactose
Disaccharides:
Sucrose - Table sugarLactose - Milk sugarMaltose - Malt sugar
Making Disaccharides:
Sucrose = glucose + fructoseLactose = 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 digestLong 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
Several covalent bonds called peptide bonds join amino acids together to form proteins.
Proteins a.k.a. polypeptidesThrough what process? How do you
build a polymer?
Proteins
Proteins differ in:–#, type & the arrangement of amino acids
Proteins
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!
Protein Function:
What do proteins do?
1. Enzymes: speed up or Increase rate of chemical reactions / lowers activation energyEx. Amylase converts
starch to simple sugar
Rates of Chemical Reaction
Energy is needed to start reaction: Activation Energy
Reactants
Products
What affects enzyme function?
pHTemperature
What do proteins do? (cont.)
2. Transport: substances inside the cell and between cells
Ex. Hemoglobin (red blood cell protein- carries Oxygen)
3. Defense: Antibodies which are used to defend the body from foreign invaders.
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.)
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 functionsSteroids: Cholesterol,
Hormones (testosterone & estrogen)
Function of Lipids (cont.)
3. Provide structure: in cells & waxy coating on plants
Saturated Fats
Called triglycerideHard & solid at room temp
Ex. Meat, Dairy, Butter, Chocolate, Animal Fats
Unsaturated Fats
“Kinked” carbon chainLiquids at room temp
Ex. Peanuts, Fish, Olive Oil
Saturated v.s. Unsaturated
Trans Fats
Worst type of fatIncreases 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 =
NucleotideTwo types
DNA & RNA
DNA
Deoxyribonucleic acidStore genetic
informationDouble helix
RNA
Ribonucleic AcidHelps synthesize
(create) proteins