Transcript CH 5 - shsbiology

CH 5
5.1
Carbon is the main ingredient of
organic molecules
The special
chemicals of life
1. Identify carbon skeletons and functional
groups in organic molecules.
• Carbon & water are most important
biomolecules to life
• Carbon has 4 e- in highest energy level
– Can therefore make 4 bonds with other atoms
– Carbon bonds with other carbons in various
shapes
• Hydrocarbons= molecules made of C & H
ONLY
– Good storage of energy (methane gas)
• Functional Groups:
– Groups of atoms that attach…giving specific
properties
2. Relate monomers and polymers.
• Biomolecules can be HUGE in number of
atoms
– Made up of smaller “chunks”=monomers
• Less than 50 different types
– Large chains of monomers= polymers
• 4 major groups of biomolecules:
– Carbohydrates, Lipids, Proteins, and Nucleic
Acids
3. Building & Breaking Polymers
• Adding monomers = dehydration reaction
(removes water)
3. Building & Breaking Polymers
• Breaking polymers= hydrolysis reaction
(water is added)
5.1 Vocabulary
•
•
•
•
•
•
•
organic molecule
inorganic molecule
hydrocarbon
functional group
hydrophilic
monomer
polymer
5.2
Carbohydrates provide fuel and
building materials.
Carbohydrate
Video Clip
Carbohydrates
• AKA- Carbs
• 2 Types:
– Provide immediate energy (sugars)
– Stored as longterm energy (starches)
• Hydrophylic due to hydroxyl groups
Describe the basic structure and
function of sugars.
• Made of C, H, and O in the ratio of 1:2:1
• Usually base shape is a carbon ring
• Simple sugars = monosaccharides
– Glucose, Sucrose, and Galactose
– Main supply of energy for cellular work
– If not used immediately, will be used to form
larger molecules (starches or lipids)
Describe the basic structure and
function of sugars cont.
• Disaccharides= two monosaccharides
bonded together
– Most common: Sucrose
• 1 glucose bonded to 1 fructose
• Common in plant saps
Describe the basic structure and
function of sugars cont.
• Polysaccharides= long chains made up of
monomers
• Ex: starch
– Plant starch = in potatoes, corn, rice
• Good energy source
• Special plant starch for structure: cellulose (we
cannot digest) is fiber
– Animal version of “starch” = glycogen
5.2 Vocabulary
•
•
•
•
•
•
•
carbohydrate
monosaccharide
disaccharide
polysaccharide
starch
glycogen
cellulose
5.3
Lipids include fats and steroids
Lipids, Oils, & Fats
Video
Characteristic of lipids
• AKA: fats (and steroids)
• Hydrophobic =avoid water (do not mix with
well)
– Act as boundaries between watery boundaries
• Serve as chemical messengers
• Serve to store energy
Structure & Function of Fats
• 3 Carbon chain(glycerol) with 3 fatty acids attached
• Saturated: contain maxi # of H & solid at room temp.,
common in animals
• Unsaturated: less than max # of H, liquid at room
temp., common in plants
• Oils= liquid at room temperature
• Insulate body for temperature
• Store energy
Structure and function of steroids.
• Lipids b/c hydrophobic but very different
• Carbon skeleton is in 4 fused rings
• Some are chemical signals (estrogen &
testosterone
• Cholesterol: essential in cell membranes
– Some forms known for causing heart disease
5.3 Vocabulary
•
•
•
•
•
•
•
lipid
hydrophobic
fat
saturated fat
unsaturated fat
steroid
cholesterol
5.4
Proteins perform most functions
in cells
Proteins
Video Clip
Proteins
•
•
•
•
10,000+ types
Each with a unique 3-D shape
Shape determines function
Built from 20 different monomers (amino
acids)
Functions of proteins.
• Found in hair, muscles
• Circulate in bloodstream to protect against
microorgansims
• Control chemical reactions in cell
Structure of amino acids and
proteins
• Amino Acids: 1 central Carbon with 4 side groups
–
–
–
–
Hydrogen atom
Carboxyl group
Amine group
? (This is different in each amino acid)
• Amino acids are linked by dehydration reactions
– Form polypeptides (100+ a.a. long)
– Each sequence produces a new protein
Factors that influence protein
shape.
• Shape determined by sequence and
environmental conditions
– Water…pushes & pulls for
hydrophylic/hydrophobic
• Other environmental changes can ruin the
shape of the protein (denaturation)…won’t
work
– Change in pH
– Change in temperature
5.4 Vocabulary
•
•
•
•
protein
amino acid
polypeptide
denaturation
5.5
Enzymes are Proteins that speed
up chemical reactions
Enzymes affect activation energy.
• Activation energy= energy added to a
compound to “weaken” bond
– prepares for chemical reaction
• Enzymes serve as biological catalysts
– Allow reactions to take place at normal cell
temperatures (with less energy)
• Names typically end in -ase
Enzymes shape & function
• Enzymes (substrate) fit into compound
(active site)
• Shape unique to reactants
– Shape can be altered like other proteins
5.5 Vocabulary
•
•
•
•
•
activation energy
catalyst
enzyme
substrate
active site
11.2
Nuclein Acids store information
in the sequence of their units
Nucleic Acid
Video Clip
Building blocks of DNA.
• 2 Types of Nucleic Acids:
– DNA (Deoxyribose Nucleic Acid)
– RNA (Ribose Nucleic Acid
• All made up of nucleotides:
– 1 Sugar
– 1 Phosphate
– 1 Nitrogen base (4 types)
Nitrogen Bases
• 2 Types of Nitrogen Bases
– Purines (2)
– Pyrimidines (2)
• Total of 4
DNA's structure and the rules for
base pairing in DNA
• Sugars and phosphates
Form “backbone”
• Nitrogen bases form
“rungs”
• DNA is a double
helix
Discovery of Structure
• 1950s Rosalind Franklin and Maurice
Wilkins discovered double helix shape
through X-rays
• James Watson and Francis Crick were
creating models of DNA… created
accurate model after seeing x-rays
– Model helped determine: purine pairs with
pyrimidine (A & T) (G & C)
11.2 Vocabulary
•
•
•
•
•
•
deoxyribonucleic acid (DNA)
nucleotide
nitrogenous base
pyrimidine
purine
double helix