1. Biology Unit 2 Study Guide
Answers

2. 1
Ionic = electrons from one molecule are given away to another molecule.
Covalent = electrons are shared between the molecules.
Polar covalent = shared unequally
Non-polar covalent = shared equally

3. 2

4. 3

5. 4 Cohesion = water bonding with itself.
Adhesion = water bonding with other substances.

6. 5

7. 6
Without it, trees and other plants would not be able to move water from deep in the ground to their leaves.
So what?
No water = no photosynthesis = dead plants

8. 7
It keeps them from having large differences in the high and low daily temperatures.

9. 8 It turns from a liquid to a gas (vaporizes) at a high temperature.
It takes a lot of energy to get the water molecules to change phases from liquid to gas.

10. 9 Oceans and other bodies of water have not evaporated.
Evaporative cooling allows organisms to cool off when hot.

11. 10

12. 11
Ice floating insulates the remaining water beneath, allowing organisms to survive the winter.
If ice sank, a large portion of our bodies of water would have frozen over, killing most life within them.

13. 12
Surface Tension

14. 13
Monomers link together to make polymers.

15. 14
Carbohydrates
Lipids
Proteins
Nucleic Acids

16. 15 Provide energy (mono, di, and poly)
Store energy for a short time (poly)
Form structures (poly)

17. 16
Mono-, Di-, and Poly- are the prefxes denoting how many sugar monomers are present.
The number of sugars can give an indication of the amount of energy stored within the molecule.

18. 17
monosaccharide

19. 18 Monosaccharide = glucose & fructose
Disaccharides = sucrose and lactose
Polysaccharides = starch, glycogen, cellulose and chitin

20. 19 Cellulose and chitin are both structural polysaccharides.
Chitin forms cell walls in fungi and exoskeletons in some animals.
Cellulose forms cell walls in plants.

21. 20 Both starch and glycogen store sugar.
Starch is the sugar storage form in plants.
Glycogen is the sugar storage form in animals.

22. 21 Starches are found in plants Potatoes Beans Plantains Corn
Actually, all green vegetables are capable of making starch.

23. 22
Glycogen is found in the muscles and livers of mammals.

24. 23 Waterproofing membranes Chemical messengers Form cell membranes
Store Energy

25. 24
Fats, oils, waxes, steroids

26. 25 Saturated fats: Unsaturated fats: Animal fats Full of hydrogens
Solids at room temp
Relatively unhealthy
Unsaturated fats:
Plant oils
Have fewer hydrogens
Are liquids at room temperature
Healthy

27. 26 The monomer of a protein = amino acid.
The polymer of a protein = polypeptide

28. 27 Amino acids are the building blocks of proteins.
They link together (via peptide bonds) to form large structures called proteins (AKA: polypeptides).
This small part linking together to form a large structure is analogous to links coming together to form a chain.

29. 28 Build muscle and bone Serve as enzymes
Fight infections (are called antibodies when doing this)
Serve as doorways into the cell.
Serve as regulators of cell activities.

30. 29 C H O N P

31. 30
DNA
RNA

32. 31
Nucleotides

33. 32
5 carbon sugar
Phosphate
Nitrogen base

34. 33
DNA has deoxyribose sugar in it.
RNA has ribose sugar in it.

35. 34
Enzymes

36. 35
Anything that speeds up a chemical reaction

37. 36 They lower the activation energy for the reaction.
They do not provide energy to the reaction…they just make the amount of energy needed to start the reaction be less.

38. 37
The amount of energy needed to start a reaction.

39. 38 Substrates are changed during enzymatic reactions.
Enzymes remain unchanged by the reaction and can be used again.

40. 39
Each enzyme has a special shape that directly matches its target substrate.
This is analogous to how each lock has a particular shaped key that opens it.
Wrong shaped key = no opened lock.

41. 40