Biology 1 Chapter 5 (Lecture) Flashcards
Critically important molecules of all living things fall into 4 main classes:
1) CHO
2) Lipids
3) Proteins
4) Nucleic Acids
Macromolecules
1) CHO
2) Proteins
3) Nucleic Acids
Polymers
Long molecule consisiting of many similar or identical building blocks linked by covalent bonds.
Monomers
The building blocks of polymers; the repeating unit of smaller molecules.
Dehyrdation Reaction
A reaction in which two molecules are COVALENTLY BONDED to each other through the loss of a water molecule. (Also called a CONDENSATION REACTION)
Enzymes
Specialized macromolecules to speed up chemical reactions in cells. (Chemical agents that slectively speed reactions without being consumed by the reaction.)
Hydrolysis
Process that disassembles polymers. It is essentially the reverse of dehydration.
Carbohydrates include…
Sugars and polymers of sugars.
Monosaccharides
The simplest carbohydrates.
Disaccharides
Double sugars. Formed by covalent bonds (glycsidic linkage)
Trademark of Sugar
Carbonyl and multiple Hydroxyl groups
Glucose
The most important sugar and is an aldose.
Carbon skeleton
3-7 carbons long.
Glucose & Fructose
Examples of hexoses.
Diasscharides
Joined by glycosidic linkages which is a covalent bond formed by a dehydration reaction. (Most common diasscharide is sucrose [glucose & fructose])
Polysaccharides
Polymers with a few hundred to a few thousand monosaccharides joined by glycosidic linkages.
Polysaccharides are important for…
1) Storage of sugar
2) Building material for structures that protect the cell or whole organism.
Storage Polysaccharides
1) Plants: Starch
2) Animals: Glycogen- Stored in liver & muscle cells. (Glycogen is polymer of glucose) (Our storage is depleted in 1 Day unless replenished by CHO)
Structural Polysaccharides
1) Cellulose
2) Chitin
Humans don’t have
***Cell Walls***
Cellulose
Polymer of glucose, but different glycoside linkages than in starch
- Major component of cell wall in plants
- Most abundant organic compund on earth
- Major constituent of Paper
- Only component of Cotton
- Few organisms possess enzymes that can digest cellulose
- Humans cannot digest cellulose
- Not a nutrient for humans, but part of a healthy diet
- Whole grains, veg, etc rich in celluluose
- “Insoluble fiber” on food packages is actually cellulose
- Some prokaryotes can digest cellulose
- Cows and termites have prokaryotes doing it for them.
Chitin
A structural polysaccharide
- Used by spiders, insects, etc to make their exoskeletons
- In cell wall of many fungi
- Used to make strong and flexible surgical thread
Lipids
- Not big enough to be considered macromolecules
- All share one important trait: mix poorly, if at all with water
- Three classes of lipids:
- Fats
- Phospholipids
- Steroids