Lesson 1: Macromolecules Flashcards
What are macromolecules made of?
Macromolecules (and nearly all molecules) are based on carbon
What bonds do carbon form?
- Carbon forms highly stable covalent bonds
- It can link to other carbon atoms and produce rings and chains that can form the backbone of complex molecules
What is the most abundant macromolecule?
PROTEINS! (They make up 15% of the cell)
What are the monomers of carbohydrates/polysaccharides?
Sugars
- Intermediate molecule: oligosaccharide
What are the monomers of fats and membrane lipids?
Fatty acids
What are the monomers of proteins?
Amino acids
- Intermediate molecule: peptide
What are the monomers of nucleic acids?
Nucleotides
- Intermediate molecule: oligonucleotide
What bonds are the macromolecules (excluding lipids) linked by?
Covalent bonds
What is condensation?
Is an energetically unfavorable reaction (requires energy) where polymers are made. Water molecule is lost/prdocuced.
What is hydrolysis?
Is an energetically favorable reaction (energy is released) where polymers are broken down. A water molecule is required for hydrolysis to occur.
Do lipids perform condensation and hydrolysis reactions?
NO!
Only carbohydrates, proteins, and nucleic acids perform condensation and hydrolysis reactions.
What is the chemical formula for carbohydrates?
(C1H2O1)n
- N can be 3, 4, 5, or 6
- Note: If n is 3, 3-carbon is called a triose
If n is 5, 5-carbon is called a pentose
If n is 6, 6-carbon is called a hexose
What are the functions of carbohydrates?
1) Sources of stored energy
2) Can transport chemical energy (energy stored in covalent bonds)
3) Can be used as carbon skeletons for many other molecules
What type of structure do carbohydrates take in an aqueous solution?
Carbohydrates take on a RING structure in aqueous solutions
How is this ring structure formed in glucose?
Aldehyde (chemical group) reacts with Carbon-5 to form a ring
What is the carbohydrate polymer in animals called?
Glycogen
What is the carbohydrate polymer in plants called?
Starch
Do polysaccharides have branched points?
YES!
Polysaccharides have branched points (not seen in the other macromolecule families)
What is the covalent bond that binds monosaccharides together?
GLYCOSIDIC BONDS
- Remember: Bonds are formed through condensation reactions where water is lost. This reaction is REVERSIBLE! Hydrolysis reactions can break glycosidic bonds and requires water as an input
Where does the water come from when two monosaccharides are joined?
A hydroxyl group is lost from one monosaccharide and a hydrogen is lost from another monosaccharide forming the water molecule
What are the different components of amino acids?
- Central carbon
- Amino group (H3N+)
- Carboxyl group (COO-)
- Single hydrogen
- The “R group” (aka side chain)
Note: 1-4 is considered the amino acid backbone (the same for each amino acid)
Note: There are 20 different R groups. So there are 20 different amino acids that make up proteins.
How can you distinguish where the central carbon is?
The central carbon is ALWAYS attached to the R group
What is the covalent bond that binds amino acids together?
PEPTIDE BONDS!
Where does the water come from when two amino acids are joined?
An oxygen molecule from the carboxyl group (COO-) and two hydrogen molecules from the amino group (H3N+) form the water molecule
