1. Biochemistry Unit Review
Part 1

2. Biomolecules “Organic” molecules have carbon.
“Inorganic” molecules do not have carbon.
Monomers are small parts that make up a large polymers.
Monomer + Monomer + Monomer = Polymer

3. Biomolecules Carbo-hydrate C, H, O Fast energy
Organic Molecule
Elements
Function
Monomer
Test
Carbo-hydrate
C, H, O
Fast energy
Monosaccharides (like glucose)
Benedict’s – glucose
Iodine - starch
Lipid
Store long-term energy, make up cell membranes
Fatty acids and glycerol
Paper bag
Protein
C, H, O, N
Growth and repair, speed up chemical reactions
Amino acids
Biuret’s
Nucleic Acid
C, H, O, N, P
DNA: carries hereditary info
RNA: makes proteins
Nucleotides
Is it living?

4. Water & pH
Water is a universal solvent – it dissolves most molecules and ions.
pH is a measure of the amount of Hydrogen ions in a solution.
pH scale goes from 0 – 14.
1-6 = Acid – the lower the pH, the stronger the acid.
Ex. 2 is a stronger acid than 5
7 = NEUTRAL – based on pure water
8-14 = Base (alkaline) – the higher the pH, the stronger the base.
Ex. 14 is a stronger base than 11

5. Enzymes
Enzymes are a special type of protein that speeds up a chemical reaction by lowering the activation energy of a reaction.
Enzymes are biological catalysts
The material an enzyme works on is called the substrate.
The pocket or groove where the substrate fits into on the enzyme is called the active site.
Enzymes are named for the substrate that they work with. Names usually end in –ase.
Enzymes can be “denatured” by a change in temperature or a change in pH.

6. Practice Questions

7. 1. A molecule that is found on the surface of most cells is responsible for communication between the cells. This molecule is made up of long chains of amino acids and is specific to each cell type. This molecule is a
lipid
carbohydrate
DNA strand
Protein

8. 2. Which statement best describes the function of a lipid in a cell?
storing and transmitting heredity
forming part of biological membranes
forming amino acid chains
storing phosphorus

9. 3. Which of the following factors is most likely to affect the function of an enzyme?
catalysts
size of beaker
proteins
temperature

10. 4. Which of the following statements best describes a function of an enzyme?
All enzymes work on all substrates.
Enzymes are specialized proteins that serve as catalysts.
Enzymes are carbohydrate-based molecules in all cells.
The structure of enzymes is changed during a chemical reaction.

11. 5. Which of the following substances would show a positive brown paper test for lipids?
apples
bacon
crackers
water

12. 6. Which pH indicates a substance that is more basic than a substance with a pH of 9?6 2 8 12

13. 7. Which of the following is a list of elements that make up the structure of a carbohydrate?
carbon, nitrogen, oxygen
hydrogen, carbon, oxygen
nitrogen, sulfur, oxygen
oxygen, carbon, phosphorus

14. 8. Which of the following is a function of proteins?
storing energy
storing waste
growth and repair
breaking chemical bonds

15. 9. Which of the following organic molecule tests is correctly paired with its organic molecule?
proteins – brown paper
glucose – biuret
starch - iodine
lipid – benedicts

16. 10. Which biomolecules store and transmit genetic information?
carbohydrates
lipids
nucleic acids
proteins

17. 11. Which of the following best describes the function of carbohydrates?
They code for proteins.
They form biological membranes.
They provide a source of energy for an organism.
They control reaction rates in a cell.

18. Biochemistry Unit Review
Part 2

19. The Cell Theory
The cell theory was developed with the help of the light microscope. The cell theory states that: 1. all organisms are composed of cells 2. cells are the basic unit of structure and function in living things 3. cells come from pre-existing cells

20. The Cell Theory
Cell Theory People: a. Anton von Leeuwenhoek  microorganisms b. Robert Hooke  named cells c. Matthias Schleiden  all plants made of cells d. Theodore Schwann  all animals made of cells e. Rudolph Virchow  new cells come from existing cells.

21. Microscopes
Total Magnification = eyepiece (ocular lens) x objective lens Eyepiece = 10x Objectives = 10x, 40x, 65x Greatest possible magnification = Ex. Total magnification 600x = Eyepiece 10x X Objective 60x Under the microscope, letters get put upside down and backwards. Ex. “e” appears as “___”.
Types of microscopes: 1. light microscope 2. scanning electron microscope 3. transmission electron microscope

22. Prokaryotes vs. Eukaryotes
Make a Venn diagram using
Nucleus
Organelles
DNA
Cell membrane
the following words: Capsule Reproduce Plants Bacteria Animals

23. Eukaryotic Organelles
Nucleus – controls the cell (where DNA is found) Ribosomes – site of protein synthesis (make proteins) Plasma (Cell) Membrane – controls what comes in and out Endoplasmic reticulum– series of channels that act as a transport system Golgi Apparatus – packs, sorts, and ships molecules Mitochondria – powerhouse; makes energy; site of cellular respiration Chloroplast – site of photosynthesis Vacuole – stores water, food and waste Cell wall – used for structure and support in plant cells

24. Eukaryotic Organelles
Plant cells are different from animal cells in three ways: 1. plant cells have a cell wall, animal cells don’t 2. plant cells have chloroplasts, animal cells don’t 3. plant cells have larger vacuole

25. Practice Questions

26. 1. If an organism does not have membrane-bound organelles, what is it called?
simple
eukaryotic
prokaryotic
complex

27. 2. Which organelle pictured is responsible for transforming energy?
a b.
c d.

28. 3. During the period from , German scientists Matthias Schleiden, Theodor Schwann, and Rudolph Virchow contributed greatly to the understanding of plant and animal cells. Their cell theory includes all of the following ideas except which one?
All living things are made of cells.
Cells are the basic units of structure and function of living things.
Cells come from pre-existing cells.
Viruses are not made of cells.

29. 4. Prokaryotic and eukaryotic cells are distinguished from each other by which of the following?
Prokaryotic cells include most cells, other than bacteria, and lack a nucleus and membrane-bound organelles.
Prokaryotic cells include mainly bacteria, and lack a nucleus as well as membrane-bound organelles.
Prokaryotic cells include most cells, other than bacteria, and contain a nucleus and membrane-bound organelles.
Prokaryotic cells include mainly bacteria, and contain a nucleus as well as membrane-bound organelles.

30. 5. Which of the cell organelles labeled below helps you determine if this is an animal cell or a plant cell?
nucleus
cell wall
ribosomes
mitochondria

31. 6. What is the function of the Golgi apparatus?
manufacture proteins
package and transport proteins
store proteins
break down proteins to release energy

32. 7. A student identifies an unknown cell as being eukaryotic
7. A student identifies an unknown cell as being eukaryotic. Which of the following did she most likely identify in order to draw this conclusion?
nucleus
cell wall
chloroplasts
cell membrane

33. 8. Which of the following best describes the function of a ribosome?
making proteins
digesting lipids, carbohydrates and proteins
storing water, proteins, salts and carbohydrates
providing structural support for the cell

34. Biochemistry Unit Exam Review
Part 3

35. Cell Membrane
The cell membrane (plasma membrane) is made up of two layers of lipids, so it is called a lipid bilayer.
Proteins can also be found inside the membrane. They can act as receptors, channels and pumps.

36. Cell Membrane
The lipid bilayer contains phospholipid molecules with non-polar tails and polar heads.
They hydrophobic tails are “water hating”, while the hydrophilic heads are “water loving”.
They are arranged in the membrane with the tails together and the heads on the outside.

37. Cell Membrane
Most biological membranes are “selectively permeable”, or some substances can pass across the membrane while others cannot.

38. Cell Transport
The selective permeability of the cell membrane is most closely associated with the maintenance of homeostasis.
Two main types of transport are passive and active.
Passive Transport – does not require energy; moves molecules from high concentration  low concentration.
Diffusion – molecules move from high  low
Osmosis – water moves from high  low
(water moves from less salt to more salt)
Facilitated Diffusion– large molecules move from high  low through a transport protein

39. Cell Transport
Active Transport – requires energy (ATP); moves substances from low concentration  high concentration.
Equilibrium – the concentration of dissolved substance is the equal throughout a system.

40. Cell Transport What happens to a cell when …
it is placed in a solution with a higher salt concentration –
it will shrink
it is placed in a solution with the same salt concentration
stay the same
it is placed in a solution with lower salt concentration –
it will swell

41. Photosynthesis
Photosynthesis is the conversion of light into chemical energy.
Equation: CO2 + H2O + Light  C6H12O6 + O2
Carbon dioxide + Water + light energy  Glucose (sugars) + oxygen
Photosynthesis occurs in the chloroplast and the sunlight required for the reaction is absorbed by the chloroplast pigment chlorophyll.
There are 2 stages to photosynthesis:
1. Light-dependent (Electron Transport Chain)
2. Calvin Cycle (Light-independent)

42. Aerobic Cellular Respiration
Cellular respiration is the process that releases energy by breaking down glucose and other food molecules in the presence of oxygen.
 Equation: C6H12O6 + O2  CO2 + H20 + ATP (energy)
Glucose + oxygen  Carbon Dioxide + water + ATP
Cellular respiration occurs in the mitochondria.
The most ATP is made during aerobic cellular respiration (36 / molecule of glucose)
There are 3 stages to aerobic cellular respiration:
Glycolysis
Kreb’s Cycle
Electron Transport Chain

43. Anaerobic Cellular Respiration
Anaerobic respiration occurs when there is a lack of oxygen for the cells.
Anaerobic respiration has 2 stages:
Glycolysis
Fermentation
There are 2 types of fermentation:
Lactic Acid
Forms lactic acid as a waste product.
Lactic acid creates sore muscles after exercising.
Alcoholic
Forms ethanol as a waste product.
Used in making bread, beer & wine.

44. Practice Questions #3 and #4

45. 1. A cell moves particles from a region of lesser concentration to a region of greater concentration by
active transport
facilitated diffusion
osmosis
passive transport

46. 2. Which conditions shown below may cause a cell to burst?

47. 3. What cell process is responsible for the transport shown below?
active transport
osmosis
facilitated diffusion
passive transport

48. 4. Which process does an organism use to move large molecules into a cell?
simple diffusion
exocytosis
endocytosis
facilitated diffusion

49. 5. Blood plasma and sea water have nearly the same salt concentration
5. Blood plasma and sea water have nearly the same salt concentration. What will happen to a red blood cell placed in pure water?
it will swell
it will disintegrate
it will shrink
it will divide

50. 6. Cells have a selectively permeable membrane
6. Cells have a selectively permeable membrane. What is the primary purpose of this membrane?
to keep all of the cytoplasm inside the cell
to control which materials enter and leave the cell
to allow photosynthesis to occur
to manufacture proteins

51. 7. Which of the following statements about osmosis and diffusion is correct?
Osmosis requires energy and diffusion does not.
Both osmosis and diffusion involve the movement of molecules from areas of higher concentration to areas of lower concentration.
Diffusion is the movement of water from areas of higher concentration to areas of lower concentration.
Osmosis is the movement of water from areas of lower concentration to areas of higher concentration.

52. 8. Which form of transport is represented in the illustration below?
facilitated transport
diffusion
active transport
osmosis

53. 9. An animal cell is placed in a solution of distilled water
9. An animal cell is placed in a solution of distilled water. If left overnight, this cell will
swell and burst
shrivel and die
undergo chemosynthesis
remain the same, since it has a cell wall to protect it

54. 1. Energy is released from ATP when the bond is broken between
two phosphate groups
ribose and a phosphate group
adenine and a phosphate group
adenine and ribose

55. 2. How are the processes of photosynthesis and respiration linked?
One takes place during the day, the other at night.
One takes place in animals, the other in plants.
The reactants of one are generally the products of the other.
They are identical, but in the reverse order of each other.

56. 3. Which of the following produces the greatest amount of ATP?
gylcolysis
Krebs cycle
Electron transport chain
fermentation

57. 4. Which of the following statements about photosynthesis is correct?
The products of photosynthesis are sugar and oxygen.
Photosynthesis occurs in mitochondria.
Sunlight is not necessary for photosynthesis to occur.
The products of photosynthesis are sugar and water.

58. 5. Which of the following is the correct sequence of events in the process of photosynthesis?
Calvin cycle, electron transport chain, absorption of light energy.
absorption of light energy, Calvin cycle, electron transport chain
electron transport chain, absorption of light energy, Calvin cycle
absorption of light energy, electron transport chain, Calvin cycle

59. 6. A cell that is capable of carrying out both photosynthesis and respiration is probably a
prokaryotic cell
mitotic cell
plant cell
animal cell

60. Light + 6H20 + 6CO2  C6H12O6 + 6O2 + ATP
7. The equation below summarizes what biological processes?
Light + 6H20 + 6CO2  C6H12O6 + 6O2 + ATP
chemophotosynthesis
fermentation
photosynthesis
cellular respiration

61. 8. During strenuous exercise, animals cannot take in enough oxygen to supply their cells with the necessary oxygen. As a result, they carry out lactic acid fermentation to supply their cells with the necessary energy. Lactic acid fermentation is a type of
anaerobic respiration
aerobic respiration
alcoholic respiration
ATP respiration