Carbohydrates
Carbohydrates
Includes sugars and polymers of sugars
Contain a carbonyl group and many hydroxyl groups
Comprised of C, H, and O
Monosaccharides: simple sugars
Molecular formulas with multiples of the unit CH2O
Most common is glucose
Nutrients and fuel for cells
Used in cellular respiration
Can serve as building blocks for amino acids, or as monomers for di- and
polysaccharides
Carbohydrates
Disaccharides: two monosaccharides joined together by covalent bonds
Most common is sucrose
Monomers of sucrose: glucose and fructose
Plants transfer carbohydrates from roots to leaves in the form of sucrose
Carbohydrates
Polysaccharides: polymer with many sugars joined via dehydration reactions
Storage polysaccharides
Plants store starch (polymer of glucose monomers)
Allows plants to store excess glucose
Animals store glycogen (polymer of glucose)
Stored in liver and muscle cells
Structural polysaccharides
Cellulose: tough substance that forms plant cell walls
Chitin: forms exoskeleton of arthropods
Practice
You are given an unknown monosaccharide to identify in the lab. The only clue you
are given is that it has 4 carbons. You (being an excellent AP bio student) figure
out the formula. What is the unknown monosaccharide?
Proteins
Formation of a Protein
Amino acid
Peptide
Polypeptide
Protein
small
large
Proteins
Protein: molecule consisting of polypeptides (polymers of amino acids) folded into
, a 3D shape
Comprised of C, H, O, N, and S
Shape determines function
Amino Acids
Molecules that have an amino group and a carboxyl group
20 different amino acids
Amino group
carboxyl group
R = variable side chain
Unique side chain (R)
General Structure
Amino Acids
Each amino acid (AA) has a unique side chain
Unique aspects of the AA are based on the side chain’s physical and chemical
properties
Side chains can be grouped as:
Nonpolar (hydrophobic)
Polar (hydrophilic)
Charged/ionic (hydrophilic)
Side chains interact, which determine the shape and function of the protein
Formation of Peptide Bonds
To form a peptide bond the carboxyl group of one AA must be positioned next to the
amino group of another AA
Peptide bond
Repetitive backbone
Side chains
Dehydration reaction
Polypeptides
Polypeptides: many AA linked by peptide bonds
Each polypeptide has a unique sequence of AAs and directionality
Each end is chemically unique
One end is a free amino group (N-terminus)
One end is a free carboxyl group (C-terminus)
Polypeptides
Remember: SHAPE determines FUNCTION
The sequence of AAs determines the 3D shape
When a polypeptide twists and folds (because of R group interaction) it forms a
protein
Quick! Think, pair share
How is the unique sequence of AAs determined for a polypeptide?
Genes
Functions of Proteins
Function of proteins include:
Antibody-help protect the body from disease
Enzyme- carry out chemical reactions or assist in creating new molecules
Messenger- transmit signals (ie hormones)
Carbohydrates
Includes sugars and polymers of sugars
Contain a carbonyl group and many hydroxyl groups
Comprised of C, H, and O
Monosaccharides: simple sugars
Molecular formulas with multiples of the unit CH2O
Most common is glucose
Nutrients and fuel for cells
Used in cellular respiration
Can serve as building blocks for amino acids, or as monomers for di- and
polysaccharides
Carbohydrates
Disaccharides: two monosaccharides joined together by covalent bonds
Most common is sucrose
Monomers of sucrose: glucose and fructose
Plants transfer carbohydrates from roots to leaves in the form of sucrose
Carbohydrates
Polysaccharides: polymer with many sugars joined via dehydration reactions
Storage polysaccharides
Plants store starch (polymer of glucose monomers)
Allows plants to store excess glucose
Animals store glycogen (polymer of glucose)
Stored in liver and muscle cells
Structural polysaccharides
Cellulose: tough substance that forms plant cell walls
Chitin: forms exoskeleton of arthropods
Practice
You are given an unknown monosaccharide to identify in the lab. The only clue you
are given is that it has 4 carbons. You (being an excellent AP bio student) figure
out the formula. What is the unknown monosaccharide?
Proteins
Formation of a Protein
Amino acid
Peptide
Polypeptide
Protein
small
large
Proteins
Protein: molecule consisting of polypeptides (polymers of amino acids) folded into
, a 3D shape
Comprised of C, H, O, N, and S
Shape determines function
Amino Acids
Molecules that have an amino group and a carboxyl group
20 different amino acids
Amino group
carboxyl group
R = variable side chain
Unique side chain (R)
General Structure
Amino Acids
Each amino acid (AA) has a unique side chain
Unique aspects of the AA are based on the side chain’s physical and chemical
properties
Side chains can be grouped as:
Nonpolar (hydrophobic)
Polar (hydrophilic)
Charged/ionic (hydrophilic)
Side chains interact, which determine the shape and function of the protein
Formation of Peptide Bonds
To form a peptide bond the carboxyl group of one AA must be positioned next to the
amino group of another AA
Peptide bond
Repetitive backbone
Side chains
Dehydration reaction
Polypeptides
Polypeptides: many AA linked by peptide bonds
Each polypeptide has a unique sequence of AAs and directionality
Each end is chemically unique
One end is a free amino group (N-terminus)
One end is a free carboxyl group (C-terminus)
Polypeptides
Remember: SHAPE determines FUNCTION
The sequence of AAs determines the 3D shape
When a polypeptide twists and folds (because of R group interaction) it forms a
protein
Quick! Think, pair share
How is the unique sequence of AAs determined for a polypeptide?
Genes
Functions of Proteins
Function of proteins include:
Antibody-help protect the body from disease
Enzyme- carry out chemical reactions or assist in creating new molecules
Messenger- transmit signals (ie hormones)
