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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`
+ H2O
glucose fructose
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`
• 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`
Lipids
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
aminogroup
carboxylgroup
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
hair wrapped around cuticles
differentbridges form
bridgesbroken
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`
• 1) Sugar
– a) Ribose or deoxyribose
• 2) At least one phosphate group
• 3) Base
– a) Nitrogen-containing
– b) Single or double ring structure`
Nucleotide Structure
Nucleotide Functions
• Energy carriers
• Coenzymes
• Chemical messengers
• Building blocks for
nucleic acids`
ATP - A Nucleotide
three phosphate groups
sugar
base
ATP
• 1) Composed of nucleotides• 2) Single- or double-stranded• 3) Sugar-phosphate backbone`
Nucleic Acids
AdenineCytosine
DNA Subunits
DNA
• 1) Double-stranded
• 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