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UNIT 1 BIOCHEMISTRY
UA
What is Biology?
Bio = life ology = the science of Biology = the science of life!
What is “life” made of?
All living things need 6 essential elements:
CHNOPS Carbon
Hydrogen NitrogenOxygenPhosphorousSulfur
Life is organic
All life is organic (contains BOTH Carbon and Hydrogen)
NaCl
Biotic vs. abiotic
Abiotic: non-living
Soil Rocks Sunlight Water
Biotic:living Animals Plants Bacteria Fungi Protists
Biological molecules (macromolecules)
Carbohydrate Lipid Nucleic acid Protein
Macromolecule structure
All macromolecules are BIG! Made of small pieces or subunits called
monomers.
Many put together = polymer.
monomer
monomer monomer monomer monomer
Carbohydrates – sugars!
Composed of: CHO in a 1:2:1 ratio Monomer: monosaccharide (mono means one)
2 = disaccharide 3 or more = polysaccharide
Function: Immediate energy, cell structure Examples: glucose, sucrose, glycogen, starch,
cellulose. How to identify: Looks like a ring
Carbohydrates – sugars!
20
cellulose fibers in plant cell wall
H bond
monosaccharide disaccharide
polysaccharide
Lipids – fats!
Composed of: CHO Monomer: glycerol and three fatty acids Function: Long term energy storage Examples: fats, oils, waxes, steroids How to identify: long chains of carbon and
hydrogen (can have rings too).
CH3
CH3
Cholesterol (a steroid)
CH3
CH3
H3C
HO
Lipids – fats!
Saturated fats: Come from animals. No double bonds between
carbons. Difficult to break down.
Unsaturated fats: Come from plants. Double bonds between carbons. Easier to break down. Trans fatty acids have been
artificially hydrogenated to make them more solid.
Phospholipids
Plasma membrane of a cell
inside of cell
outside of cell
R
P
O
O O–phosphategroup
fatty acids
HCH
HCHH
CH
O
OC
HCH
HCH
HCH
HCH
HC
O
HCH
HCH
HCH
HCH
HCH
HCH
HCH
HCH
HCH
HCH
HCH
HCH
HCH
HCH
HCH
HCH
H
HCH
HCH
HCH
HCH
HC
HC
HCH
HCH
HCH
HCH
HCH
HCH
HCH
H
Phospholipid structure
OC
polar head
glycerol
nonpolar tails
Phospholipids make up the cell membrane.
Polar (charged) head likes water (hydrophilic).
Non-polar (uncharged) tail hates water (hydrophobic)
Nucleic Acids
Composed of: CHONP
Monomer: nucleotide
Function: store and pass genetic information Examples: DNA and RNA
How to identify: A nucleotide has 3 parts!
Proteins
Composed of: CHON Monomer: amino acid
R-group makes them unique
Function: make cell parts and carry out chemical reactions Examples: enzymes, hemoglobin, melanin,
keratin, insulin How to identify: each amino acid has a N!
Proteins
Proteins are chains of amino acids that fold up into a specific shape. Shape determines function!
Amino acids
Enzymes (special proteins)
Enzymes make reactions go faster! Catalyst – substance that speeds up a reaction.
Lower activation energy – energy required to cause a reaction.
Enzymes (special proteins)
Enzymes can synthesize or breakdown molecules. Important terms: substrate, product, enzyme-substrate complex,
active site
substrate
enzyme enzymeEnzyme-substrate complex
active site
products
Enzymes (special proteins)
Example: Catalase in liver. Catalase breaks down harmful hydrogen peroxide into water and oxygen!
Hydrogen peroxide (H2O2)
Catalase CatalaseEnzyme-substrate complex
active site
H2O and O2
Enzymes (special proteins)
Characteristics of enzymes: Specific substrate
Specific temperature If they are heated too much they unfold =
denature!
Specific pH
Specific shape
Reusable
pH
Water can separate to make ions. OHHOH 2
Acid
Base
Increasin
g [H
+]In
creasing
[OH
–]
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
hydrochloric acid (HCI)
stomach acid
lemon juice
Coca-Cola, beer, vinegar
tomatoes
black coffee
urine
pure water, tears
seawater
baking soda, stomach antacids
Great Salt Lake
household ammonia
bicarbonate of soda
oven cleaner
sodium hydroxide (NaOH)
normal rainwater
saliva
human blood
milk of magnesia
[H+]
[OH–]
neutral pH[H+] =
[OH–]
Base Acid
Hydrogen ionHydroxide ionWater
Buffer: Keeps pH stable (we have a buffer in our blood).
