Transcript PPT 2 Biochem

Chapter 4b
Carbon Compounds In Cells
Organic Compounds
Hydrogen and other elements
covalently bonded to carbon
Carbohydrates
Lipids
Proteins
Nucleic Acids `
Carbon’s Bonding Behavior
• 1) Outer shell of
carbon has 4
electrons; can
hold 8
• 2) Each carbon
atom can form
covalent bonds
with up to four
atoms`
Structural Representations
Bonding Arrangements
• 1) Carbon atoms
can form chains or
rings
• 2) Other atoms
project from the
carbon backbone`
Functional Groups
• 1) Atoms or clusters of atoms that are
covalently bonded to carbon backbone
– a) Give organic compounds their different
properties`
Examples of Functional
Groups
Hydroxyl group
- OH
Amino group
- NH3+
Carboxyl group
- COOH
Phosphate group
- PO3-
Sulfhydryl group
- SH`
Functional Groups
Carbohydrates
Monosaccharides
(simple sugars)
Oligosaccharides
(short-chain carbohydrates)
Polysaccharides
(complex carbohydrates) `
Monosaccharides
• 1) Simplest carbohydrates
• 2) Most are sweet tasting, water soluble
• 3) Most have 5- or 6-carbon backbone
Glucose (6 C)
Fructose (6 C)
Ribose (5 C)
Deoxyribose (5 C)`
Two Monosaccharides
glucose
fructose
Monosaccharide
Disaccharides
• 1) Type of
oligosaccharide
• 2) Two
monosaccharides
covalently
bonded
• 3) Formed by
condensation
reaction`
glucose
fructose
+ H2O
sucrose
Sucrose Formation
Polysaccharides
• 1) Straight or branched chains of many
sugar monomers
• 2) Most common are composed entirely
of glucose
– a) Cellulose
– b) Starch (such as amylose)
– c) Glycogen`
Cellulose & Starch
• 1) Differ in bonding patterns between
monomers
– a) Cellulose - tough, indigestible, structural
material in plants
– b) Starch - easily digested, storage form in
plants`
Cellulose and Starch
Starch Cellulose
Glycogen
• 1) Sugar storage form in animals
– a) Large stores in muscle and liver cells
• 1. When blood sugar decreases, liver
cells degrade glycogen, release
glucose`
Chitin
• 1) Polysaccharide
– a) Nitrogen-containing groups attached to
glucose monomers
– b) Structural material for hard parts of
invertebrates, cell walls of many fungi`
Lipids
• 1) Most include fatty acids
– a) Fats
– b) Phospholipids
– c) Waxes
• 2) Sterols and their derivatives have no
fatty acids
– a) Tend to be insoluble in water`
Fatty Acids
• 1) Carboxyl group (-COOH) at one end
• 2) Carbon backbone (up to 36 C atoms)
– a) Saturated - Single bonds between
carbons
– b) Unsaturated - One or more double
bonds`
Three Fatty Acids
Fats
• 1) Fatty acid(s)
attached to
glycerol
– a) Triglycerides
are most
common`
Triglyceride
Phospholipids
• 1) Main components of cell
membranes`
Phospholipid
Sterols and Derivatives
• 1) No fatty acids
• 2) Rigid
backbone of four
fused-together
carbon rings
• 3) Cholesterol most common
type in animals`
Cholesterol
Waxes
• 1) Long-chain fatty acids linked
to long chain alcohols or carbon
rings
– a) Firm consistency, repel water
– b) Important in water-proofing`
Amino Acid Structure
carboxyl
group
amino
group
R group
Properties of Amino Acids
• 1) Determined by the “R group”
• 2) Amino acids may be:
– a) Non-polar
– b) Uncharged, polar
– c) Positively charged, polar
– d) Negatively charged, polar`
Amino Acids
Protein Synthesis
• 1) Protein is a chain of amino acids
linked by peptide bonds
– a) Peptide bond
• 1. Type of covalent bond
• 2. Links amino group of one amino
acid with carboxyl group of next
• 3. Forms through condensation
reaction`
Peptide Bond
Primary Structure
• 1) Sequence of amino acids
• 2) Unique for each protein
• 3) Two linked amino acids = dipeptide
• 4) Three or more = polypeptide
• 5) Backbone of polypeptide has N atoms:
-N-C-C-N-C-C-N-C-C-N-`
A Permanent Wave
bridges
broken
hair wrapped
around cuticles
different
bridges
form
Primary Structure
Secondary/Tertiary
Quaternary
Studying Spider Silk
Enzyme Structure and
Function
1) Enzymes are catalytic molecules
a) They speed the rate at which
reactions approach equilibrium`
Four Features of Enzymes
1) Enzymes do not make anything
happen that could not happen on its
own. They just make it happen much
faster
2) Reactions do not alter or use up
enzyme molecules`
Four Features of Enzymes
3) The same enzyme usually works for
both the forward and reverse
reactions
4) Each type of enzyme recognizes and
binds to only certain substrates`
Nucleotide Structure
• 1) Sugar
– a) Ribose or deoxyribose
• 2) At least one phosphate group
• 3) Base
– a) Nitrogen-containing
– b) Single or double ring structure`
Nucleotide Functions
• Energy carriers
• Coenzymes
• Chemical messengers
• Building blocks for
nucleic acids`
ATP - A Nucleotide
base
three phosphate groups
sugar
ATP
Nucleic Acids
Cytosine
Adenine
• 1) Composed of nucleotides
• 2) Single- or double-stranded
• 3) Sugar-phosphate backbone`
DNA Subunits
DNA
• 1) Doublestranded
• 2) Consists of four
types of
nucleotides
– a) A bound to T
– b) C bound to G`
DNA Structure
RNA
• 1) Usually single strands
• 2) Four types of nucleotides
– a) Unlike DNA, contains the base uracil
in place of thymine
• 3) Three types are key players in
protein synthesis`
DNA/RNA