i chapter 2: the chemical context of life -...

AP Biology Reading Guide Fred and Theresa Holtzclaw

Chapter 2: The Chemical Context of Life

Copyright © 2010 Pearson Education, - 1

I Chapter 2: The Chemical Context of Life

This chapter covers the basics that you may have learned in your chemistry class. Whether your teacher goes over this chapter, or assigns it for you do review on your own, the questions that follow should help you focus on the most important points.

Concept 2.1 Matter consists of chemical elements in pure form and in combinations called compounds

1. Define and give an example of the following terms: matter

element

compound

2. What four elements make up 96% of all living matter?

3. What is the difference between an essential element and a trace element?

essential element

trace element

Concept 2.2 An element's properties depend on the structure of its atoms

4. Sketch a model of an atom of helium, showing the electrons, protons, neutrons, and atomic nucleus.

5. What is the atomic number of helium? Its atomic mass? -

6. Here are some more terms that you should firmly grasp. Define each term. neutron

proton

electron

atomic number

6

C12




atomic mass

isotope

electron shells

energy

7. Consider this entry in the periodic table for carbon.

What is the atomic mass?---atomic number? ---

How many electrons does carbon have? neutrons? _

8. Which is the only subatomic particle that 1s directly involved m the chemical reactions between atoms?

9. What is potential energy?

10. Explain which has more potential energy in each pair:

a. boy at the top of a slide/boy at the bottom

b. electron in the first energy shell/electron in the third energy shell

c. water/glucose

Sodium11Na




11. What determines the chemical behavior of an atom?

12. Here is an electron distribution diagram for sodium:

a. How many valence electrons does it have? Circle the valence electron(s).

b. How many protons does it have? --

Concept 2.3 Theformation andfunction of molecules depend on chemical bonding between atoms

13. Define molecule.

14. Now, refer back to your definition of a compound and fill in the following chart:

Molecule? (y/n) Compound? (y/n) Molecular Formula Structural FormulaWater

Carbon dioxide

Methane

02 02

15. What type of bond is seen in 02? Explain what this means.

16. What is meant by electronegativity?

17. Explain the difference between a nonpolar covalent bond and a polar covalent bond.

''




18. Make an electron distribution diagram of water. Which element is most electronegative? Why is water considered a polar molecule? Label the regions that are more positive or more negative. (This is a very important concept. Spend some time with this one!)

19. Another bond type is the ionic bond. Explain what is happening in the figure below (2.14):

+

20. What two elements are involved above?

21. Define anion and cation. In the preceding example, which is the anion?

22. What is a hydrogen bone!? Indicate where the hydrogen bond occurs in this figure.

23. Explain van der Waals interactions. Though they represent very weak attractions, when these interactions are numerous they can stick a gecko to the ceiling!




24. Here is a list of the types of bonds and interactions discussed in this section. Place them in order from the strongest to the weakest: hydrogen bonds, van der Waals interactions, covalent bonds, ionic bonds.

STRONG

WEAK

25. Use morphine and endorphins as examples to explain why molecular shape is crucial in biology.

Concept 2.4 Chemical reactions make and break chemical bonds

26. Write the chemical shorthand equation for photosynthesis. Label the reactants and theproducts.

27. For the equation you just wrote, how many molecules of carbon dioxide are there?

How many molecules of glucose? How many elements in glucose? _

28. What is meant by dynamic equilibrium? Does this imply equal concentrations of each reactant and product?

Testing Your Knowledge: Self-Quiz AnswersNow you should be ready to test your knowledge. Place your answers here:

1. --2. -3.

--4. --5. --6.

--7. --

8. --- -

AP Biology Reading Guide Fred and Theresa

Chapter 3: Water and the Fitness of the

Copyright © 2010 Pearson Education, -

....

I Chapter 3: Water and the Fitness of the Environment

Concept 3.1 Thepolarity of water molecules results in hydrogen bonding

.,,

1. Study the water molecules at the right. On the central molecule, label oxygen (0) and hydrogen (H).

2. What is a polar molecule? Why is water considered polar?

3. Now, add + and - signs to indicate the charged regions ofeach molecule. Then, indicate the hydrogen bonds.

4. Explain hydrogen bonding. How many hydrogen bonds can a single water molecule form?

Concept 3.2 Four emergent properties of water contribute to Earth's fitness for life

Hydrogen bonding accounts for the unique properties of water. Let's look at several.

Cohesion

5. Distinguish between cohesion and adhesion.

6. What is demonstrated when you see beads of water on a waxed car hood?

7. Which property explains the ability of a water strider to walk on water?

Moderation of Temperature

8. The calorie is a unit of heat. Define calorie.

9. Water has high specific heat. What does this mean? How does water's specific heat compare to alcohol's?

10.Explain how hydrogen bonding contributes to water's high specific heat.




11. Summarize how water's high specific heat contributes to the moderation of temperature. How is this property important to life?

12. Define evaporation. What is heat of vaporization? Explain at least three effects of this property on living organisms.

Expansion upon Freezing

13. Ice floats! So what? Consider what would happen if ponds and other bodies of water accumulated ice at the bottom. Describe why this property of water is important.

14. Now, explain why ice floats. Why is 4°C the critical temperature in this story?

Solvent of Life

15. Review and define these terms:solvent

solution

solute

16. Consider coffee to which you have added sugar. Which is the solvent? The solute?

17. Explain why water is such a fine solvent.

18. Define hydrophobic and hydrophilic.

19. You already know that some materials, such as olive oil, will not dissolve in water. In fact, oil will float on top of water. Explain this property in terms of hydrogen bonding.

·




20. Now, let's do a little work that will enable you to prepare solutions. Read the section on solute concentrations carefully, and show the calculations here for preparing a I-molar solution of sucrose. Steps to help you do this follow. The first step is done for you. Fill in the rest.

Steps to prepare a solution:

a. Write the molecular formula.

b. Use your periodic table to calculate the mass of each element. Multiply by the number of atoms of the element. (For example, 0 has a mass of 16. Therefore one mole of O has a mass of 16 x 11 = 176 g/mole.)

c. Add the masses of each element in the molecule.

d. Add this mass of the compound to water to bring it to a volume of 1 liter. This makes 1 liter of a 1-M (1 molar) solution.

21. Can you prepare 1 liter of a 0.5-molar glucose solution? Show your work here.

22. Define molarity.

Concept 3.3 Acidic and basic conditions affect living organisms

23. What two ions form when water dissociates?

You should have answered "hydronium (H30+) and hydroxide ions (OH-)" inthe preceding question. However, by convention, we will represent the hydronium ion as H+.

24. What is the concentration of each ion in pure water at 25°C?

25. Water has a pH of 7. pH is defined as the negative log of the hydrogen ion concentration [H+]. Can you now see how water is assigned a pH of 7?

26. To go a step further, the product of H+ and OH- concentrations is constant at 10-14•

[H+}[OH-}= 10-14




Water, which is neutral with a pH of 7, has an equal number of H+ and OH- ions. Now, defineacid

base

27. Because the pH scale is logarithmic, each numerical change represents a IOX change in ion concentration.

a. So, how many times more acidic is a pH of 3 compared to a pH of 5?

b. How many times more basic is a pH of 12 compared to a pH of 8?

c. Explain difference between a pH of 8 and a pH of 12 in terms of H+ concentration.

28. On the pH chart, label pH 1-14. Label neutral, acid, base. Indicate the locations of pure water, urine, gastric juice, and bleach.

29. Even a slight change in pH can be harmful! How do buffers moderate pH change?

30. Exercise will result in the production of CO2, which will acidify the blood. Explain the buffering system that minimizes blood pH changes.

31. Acid precipitation is increasing. Explain its sources.

32. Discuss how CO2 emissions affect marine life and ecosystems.


1. --

2. --

3. --

4. --5. -- 6. --

7. --8. --

a mix.ea In

M

Determining the Molarity of a Solution

Molarity:The molar concentration of a solution, usually expressed as the number of moles of solute per liter of solution.

Components Needed to Make a

Solution: Molar Mass:Found by adding up the masses from the periodic table for each atom present in the chemical formula. The units are g/mol.

For example: N H3 would be 14 + 1+ 1+1 = 17g/mol

Volume:How much do you need to have? How much do you want to have? Units are liters.

Molarity:The strength of a solution based on the amount of a substance dissolved in a liter of solution (usually distilled water). This can be calculated or given. The u nits are moijliter, moif L, or just M.

The amount of a substance that you need to make a solution to a desired molarity. This can be calculated or given. The units are gram.

Equation:Molarity: Grams of Solute

(Molar Mass)(Volu me)

Example problems: Sally wants to make 1.0L of a 1.0M solution of NaCl. How would she do this?

\J -=- \.0L gra rn:s 06 .solu.Je " ?fi:: I.OM (J ::(M'f),t l"1'1VJ -'7 (1.0'f."1'X5i .S9 lmo1Y LOLJ :: .NM = 5'B.5a/ rnol a s o+ No.Cl Sffi\)O Pel

- -----Jayson wants to make 1.0L of a 0.4M solution of Mglz. How would he do this?,af Hffie,(= I .OL &:: s :: M1MMJ( \J) .. .

JV\ -= A iT£l (.4 rnai )t.).. 2.1 9) moll I.0 L) =lo+ fng )to..,uc) .

MM = 2<) <gq l0tc1 ed1SSct"ed 1A 1. 0------Staci wants to make SOOm L of a 1.SM solution of Cu Cl. How would she do this? _

'f ::- ,5coi.. s '; ? s =- Ovi':(m')(Vl::. I.SY'lo\ J L (l.Srnc.q L'f qq.O qlrtt'l \'i.SCO LJ {] l\ 1 3 o ' C,uCI:shl.o be

\"\\'V\ qq 9hoo\ cl1sso1-1eJ \" • 5 c.;i- ----- George has 64.3g of LiBr. Ifhe dissolves this in 1.0L of water, what molarity of LiBr _

would he make? 11 1.4 ::> g7 = j '.) -=; lY ,;:, :: I ,S3s .,. lP4 . 3 8 M · lN Y11\'J') (42.0 ) mo I.O L)

\j ,\.O LMM :42 91ffld

Practice Problems:

1) Linda mixes 90.0g of N H4NQ3 in 1.SL of distilled water. What is the molarity of her solution?

2) Jeremiah needs a 0.30M of Na2C03. He was told to make 2.S L of this solution to be used in lab. How many grams of sodium carbonate should he use?

3) Suzanne wants to make a 2.0M solution of CaS04 but she only needs O.S L of the solution. How many grams of calcium sulfate should she add?

4) Xavier only has 14.7g of MgS in the cabinet. Ifhe makes 0.20L of solution, what is the molarity he has?

5) Eric found a bottle of ZnClz that he can use to make a 1.0L solution for an upcoming chemistry lab. The bottle only contains 61.2g, so the highest molarity solution he will be able to make is ...

6) Lucy needs a.SOL of a 9.0M solution of Na OH. How much sodium hydroxide should she mix with the distilled water?

7) To make a 0.40M solution of AgNQ3, Samson mixed 33.98g with distilled water. How much of the solution did he make? (hint: look for volume)


Chapter 4: Carbon and the Molecular Diversity of


---,-,.,--,------"" CH4 A,.."Atmosphere"

(I

:· ».Water vapor->----- - ,Electrode

'.

.--- LI ,...',.b'- IV1t.'). . -.cl, it.

JJ iyCondenser

/

tCooled wate J ;-· /j. . !< "-_;

10

Jcontaining\ u ;'..! ··..;. Coldorganic'--molecules I : water

\--t

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.,

Sample forchemical analysis

I Chapter 4: Carbon and the Molecular Diversity of Life

Concept 4.1 Organic chemistry is the study of carbon compounds

1. Study this figure of Stanley Miller's experiment to simulate conditions thought to have existed on the early Earth. Explain the elements of this experiment, using aITows to indicate what occurs in various pa1ts of the apparatus.

2. What was collected in the sample for chemical analysis? What was concluded from the results of this experiment?

Concept 4.2 Carbon atoms canform diverse molecules by bonding tofour other atoms

3. Make an electron distribution diagram of carbon. It is essential that you know the answers to these questions:

a. How many valence electrons does carbon have?

b. How many bonds can carbon f01m?

b. What type of bonds does it f01m with other elements?

4. Carbon chains fo1m skeletons. List here the types of skeletons that can be formed.

5. What is a hydrocarbon? Name two. Are hydrocarbons hydrophobic or hydrophilic?

H I _

"




6. In Chapter 2 you learned what an isotope is. Since students often confuse this word with isomer, please define each te1m here and give an example.

Definition Exampleisotope

isomer

7. Use this figure to identify the three types of isomers. For each type, give a key character and an example.

H H H H HL.I I I I-c=c-c-c-c-

HIl I I IH H .H H H

H

tt 1,y uH -iCH

IIH-C-C-C-

HI I IH H H

8. Give one example of enantiomers that vary in their phaimacological effect.

H X'cffl< c/

X / H

Concept 4.3 A small number of chemical groups are key to thefunctioning of biological molecules

9. Here is an idea that will recur throughout your study of the function of molecules: Change the strncture, change the function. You see this in enantiomers, you will see it in proteins and enzymes, and now we are going to look at testosterone and estradiol. Notice how similar these two molecules are, and yet you know what a vastly different effect each has. Label each molecule in the sketch below, and circle the differences.

OHCH3

•HO

10. Define functional group.

1. 2. 3. 4. 5. 6. 7.

HO,,-,::::0'CHH-C-C-OH

I I

IN H

I

-·-H--.. -·---/"" H




11. There are seven functional groups. Complete the following chaii.

Hydroxyl Carbonyl Carboxyl Amino Sulfltydryl Phosphate MethylStrncture

Example

Functional Properties

12. You will need to master the chart and the information in it. Using the functional groups above, see if you can answer the following prompts:

a. -NH2

b. Can form cross-links that stabilize protein strncture

c. Key component of ATP

d. Can affect gene expression

e. CH3

f. Is always polar

g. Determines the two groups of sugars

h. Has acidic properties

i. -COOH

j. Acts as a base

k. Circle and identify three functional groups in the molecule shown above.


----- -------- -----

AP Reading GuideFred and Theresa

Chapter 5: The Structure and Function of Large Biological


Chapter 5: The Structure and Function of Large Biological Molecules

Concept 5.1 Macromolecules arepolymers, builtfrom monomers

1. The large molecules of all living things fall into just four main classes. Name them.

2. Circle the three classes that are called macromolecules. Define macromolecule.

3. What is a polymer?

a monomer?

4. Monomers are connected in what type of reaction? What occurs in this reaction?

5. Large molecules (polymers) are conve1ted to monomers in what type of reaction?

6. The root words of hydrolysis will be used many times to fmm other words you will learn this year. What does each root word mean?

hydro-

lysis

7. Consider the following reaction:

a. The equation is not balanced; it is missing a molecule of water. Write it in on the con-ect side of the equation.

b. So, what kind of reaction is this?

c. Is C6H1206 (glucose) a monomer, or a polymer?

d. To summarize, when two monomers are joined, a molecule of is always removed.


- 1

C

H0) H 'o

·rH-C-OH

IHO-C-H

l .-H ·1-O-H• H-C-OH

IH-C-OH

IH

<c-1' ' -H-C-OH

IHO-C-H

I

'T

O-C-H"1=H-C-OH

IH-C-OH

IH

HI

H-C-OH1·HO -C-H

IH-C-OH

IH-C-OH

IH-C-OH

• L=O--'

IH



Concept 5.2 Carbohydrates serve asJuel and building material

8. Let's look at carbohydrates, which include sugars and starches. First, what are the monomers of all carbohydrates?

9. Most monosaccharides are some multiple of (CH20). For example, ribose is a 5-carbon sugar with the fo1mula C5H1005. It is a pentose sugar. (From the root penta-, meaning 5.) What is the f01mula of a hexose sugar?

10. Here are the three hexose sugars. Label each of them. Notice that all sugars have the same two functional groups. Name them:

C=O ---------OH --------

11. What is the difference between an aldehyde sugar and a ketone sugar?

12. So, as a quick review, all of these sugars have the same chemical fo1mula: C6H1206. What term did you learn in Chapter 3 for compounds that have the same molecular fo1mulas but different structural fo1mulas?

HOH




13. Here is the abbreviated ring structure of glucose. Where are all the carbons?

Pay attention to the numbering system. This will be imp01tant as we progress in our study. Circle the number 3 carbon. Put a square around the number 5 carbon.

Notice that two monomers are joined to make a polymer. Since the monomers are monosaccharides, the polymer is a disaccharide . Three disaccharides are important to us with the fo1mula C12H2201 1 . Name them below and fill out the chait.

Disaccharide F01med from which two monosaccharides? Found where?

15. Have you noticed that all the sugars end in -ose? This root word means _

16. What is a glycosidic linkage?

17. Here is a molecu le of starch, which shows 1-4 glycosidic linkages. Translate and explain this te1minology in te1ms of carbon numbering .

I- -51HH. HHH ··· · •· •••••· HH

H-cTo-c, Iy e'- I_,.,c'- Iy e-...... I_,.,c, I y e'- I _,.,c'- I y e'- IyHIII I HI .H . I HI . HI HI Ht JHJH

1 _ _ _ .-cc.. .•.. 1c . · 1 . ccc .nc1. cI IHh·•·· H ·h• < HHH H h H!"i hI




18. There are two categories of polysaccharides. Name them and give examples.

Type of Polysaccharide Examples

19. Why can you not digest cellulose? What organisms can?

20. Let's review some key points about the carbohydrates. Each prompt below describes a unique carbohydrate. Name the correct carbohydrate for each.

a. Has 1-4 B glucose linkages

b. Is a storage polysaccharide produced by vertebrates; stored in your liver

c. Two monomers of this form maltose

d. Glucose +----fo1m sucrose

e. Monosaccharide commonly called "fruit sugar"

f. "Milk sugar"

g. Structural polysaccharide that gives cockroaches their crunch

h. Malt sugar; used to brew beer

1. Structural polysaccharide that comprises plant cell walls

Concept 5.3 Lipids are a diverse group of hydrophobic molecules

21. Lipids include fats, waxes, oils, phospholipids, and steroids. What characteristic do all lipids share?

22. What are the building blocks offats? Label them on this figure.

AP Reading Chapter 5: The Strncture and Function of Large Biological


Fred and Theresa Holtzclaw

23. If a fat is composed of 3 fatty acids and 1 glycerol molecule, how many water molecules will be removed to f01m it? Again, what is this process called?

24. On the figure with question 22, label the ester linkages.

25. Draw a fatty acid chain that is 8 carbons long and is unsaturated. Circle the element in your chain that makes it unsaturated, and explain what this means.

26. Name two saturated fats.

27. Name two unsaturated fats.

28. Why are many unsaturated fats liquid at room temperature?

29. What is a transfat? Why should you limit them in your diet?

30. List four impo1tant functions of fats.

31. Here is a figure that shows the strncture of a phospholipid. Label the sketch to show the phosphate group, the glycerol, and the fatty acid chains. Also indicate the region that is hydrophobic and the region that is hydrophilic.

32. Why is the "tail" hydrophobic?


Chapter 5: The Strncture and Function of Large Biological

_ __HO


33. Which of the two fatty acid chains in the figure with question 31 is unsaturated? Label it. How do you know it is unsaturated?

34. To summarize, a phospholipid has a glycerol attached to a phosphate group and two fatty acid chains. The head is hydrophilic, and the tail is hydrophobic. Now, sketch the phospholipid bilayer structure of a plasma membrane. Label the hydrophilc heads, hydrophobic tails, and location of water.

35. Study your sketch. Why are the tails all located in the interior?

36. Some people refer to this strncture as three hexagons and a doghouse. What is it?

37. What are other examples of steroids?

Concept 5.4 Proteins have many structures, resulting in a wide range of functions

38. Table 5.1 is loaded with important information. Select any five types of proteins and summarize each type here.

Type of Protein Function Example




39. Enzymes are an imp01tant type of protein. They will be studied in Chapter 8. For now, use this sketch to review what you know about enzymes. Label the active site, the substrate, and the products. Show what happens to water.

40. Is this reaction dehydration synthesis or hydrolysis?

41. The monomers of proteins are amino acids. Sketch an amino acid here. Label the alpha or central carbon, amino group, carboxyl group, and R group.

42. What is represented by R? How many are there?

Nonpolar

efHCH3

H,w- --c,'o,o-7

THl _,oH,w-y-c'o·

C 3.,...CH3

fH ,l'H W -C-C-

'-. b-

1va1 or vJ

tt1w-y,-c'o H

Leucine (LeiJ'or' L)

1HI z ;oTH.,TH2

H3C-CI-I OH N•-!-c'

l'o-H

Glycine (Gly or G)TH3

sI

H

Alanine (Ala or A). Valine · lsoleucine (lie or I. )

H1w-{.-cTH2CHz 0 9CHz 0

H N•-i:·-c'H0- ' . :'t,-

Methionine(Met or M)

Phenylalanine(Phe or F)

Praline (Pro or P)

Polar

9H2 ,,_oH,r-T-c\,-

HSerine (Sel°or S)

OHI

Electricallycharged

Acidic Basic

NH •

'fHzI ' i NH2*

THz9H2

9H2 _ _,aH 3w-9-c::,

H

9H2

9H2

HI

H N"-6 c"CHz 0

Aspartic acid Glutamic acid (Asp.or D). (Glu:or E):,::: "o-

LysineArginineHistidine (Lys or K)(Arg or R)(His or'H)

Copyrigh: ® 2008 Pearson Educa1ion, Inc., publishing ns Pearson Benjamin Cummings..

H-N-C-C-N-c-cN-,C-C-OH1 rfH¢TH

OH

r , rH 9·I R I III n

H OH 0




43. Study the figure. See if you can understand why some R groups are nonpolar, some polar, and others electrically charged (acidic or basic). If you were given an R group, could you place it in the COITect group? Work on the R groups until you can see common elements in each catego1y.

44. Define these te1ms:

dipeptide

polypeptide

peptide bond

Label each of these terms on the diagrams.




45. There are four levels of protein strncture. Refer to Figure 5.21, and summarize each level in the following table.

Level of Protein Structure Explanation ExamplePrimary (1°)

Secondary (II0

)

Alpha helix

Beta pleated sheetTe1tiaiy (III0

)

Quaternary (IV0

)

46. Label each of the levels of protein strncture on this figure.


Chapter 5: The Stmcture and Function of Large Biological


.,._---4 0IIHO-CICH2

47. Enzymes are globular proteins that exhibit at least tertiary stmcture. On this figure, identify and explain each interaction that folds this portion .

48. Do you remember when, in Chapter 4, we said, "Change the structure, change the function"? Explain how that principle applies to sickle-cell disease. Why is the stmcture changed?

49. Besides mutation, which changes the primary stmcture of a protein, protein structure can be changed by denaturation. Define denaturation, and give at least three ways a protein may become denatured.

50. Chaperone prot eins or chaperonins assist in the proper folding of proteins. Annotate this figure to explain the process.




I

p·· ----......·o-to-ctt, 00

/,._ ,

'',!'z 0

.,....c..... ctl HJI .... c.....c .,... CHJ HH 'C...CHI!!I \lIII

0..,c,,,.,..a, 0 c,N.,... cu0.,c.._ ,,,cHv

HHH

'tt'z;.".... C"'c"'".Q'N'C"c'rmHC tiI · HC IiI\ _.. c.,,. ,,_,.CH ' - C'N ?'c'tlHl

Ott

nOCtt, 0 OH

-1 ··t1t ';NI,H lr T H

011 H

HOCt O OH

.ki;' 'ihj ,H !J r l H Otl OH

Concept 5.5Nucleic acids store and transmit hereditary information

DNA and RNA will be the core topics of Chapter 17. For now, you should just review the general functions and know the components.

51. The flow of genetic information is from DNA 7 RNA7 protein. Use this figure to explain the process. Label the nucleus, DNA, mRNA, ribosome, and amino acids.

52. The components of a nucleic acid are a sugar, a nitrogenous base, and a phosphate group. Label each on the figure below.

53. You may recall that early in this chapter we looked at the numbering system for the carbons of a sugar. Label the end of the strand on the left side of the figure below that has the number 5 sugar 5' and the other end of the chain 3'.




54. Notice that there are five nitrogen bases. Which four are found in DNA?

55. Which four are found in RNA?

56. How do ribose and deoxyribose sugars differ?

57. To summarize, what are the three components of a nucleotide?

58. Here is a model of DNA, which was proposed by James Watson and Francis Crick. What is this shape called?

59. Why are the strands said to be antiparallel?

60. What two molecules make up the "uprights"?


Chapter 5: The Stmcture and Function of Large Biological


61. What molecules make up the mngs?

62. For the two nucleotides of DNA below, provide the complementary base.A C-

63. In a DNA double helix, a region along one DNA strand has this sequence of nitrogenous

bases: 5'-T A G G C C T-3'

Write the complementary strand. Indicate the 5' and 3' ends of the new strand.


1. --2. --

3. --

4. --5.---6.-

7.--

- -




- ·- . .

r

J

I

I-w1 Important energy so

I { ·r

This summary tablefrom the Chapter 5 Review is an excellent study tool. Use it to organize material from this chapter in your mind.

Large Biological Molecules-- . - · -•--...-aM -

Concept 5.2Ca rbohvdratcs serve as fuel and building. material

, Components-....-- ---"'-,·-- ··-----.

---'

CHzO H

H ,OH H

HO I · , OH

Exam ples' -.-· . ------! Monosaccharidcs: gl ucose,

fructose

! .. - . . . - ·-.

Functions

Fuel; carbon sources that can be converted to other molecules or combined into polymers

I_ _E:h ide : lacto -=-- tc : , _ _ -- -----···-·-

H OH

Monosaccharide monomer; Polysaccharides: I

• Cellulose (plants) ! ,Strengthens plant cell walls• Starch (plants) • Stores glucose for energy

Concept 5.3Lipids are a diverse groupof hydrophobic molecules

Glycerol

I . J}I

• Glycogen (animals)• Chitin (animals and fungi)

' Triacylglycerols (fats or oils): glycerol + 3 fatty acids

• Stores glucose for energy• Strengthens exoskeletons

and fungal cell walls

urce

and arc not macromole cules ' 3 fatty acids_. _ j

'--Hea dwith®

_'(?acids

Phospholipids: phosphate group+ 2 fatty acids

Lipid bilayers of mcmbnrnc s

• (Hydrophobic

Hydrophilic ,.• ;; 2 !Jtty::,1. 1 tails:1.•!+:+' ;i

heads • " "

Steroid backbone

Steroids: fou r fused rings with attached chemical groups

, Component of cell membranes (cholesterol)

• Signals that travel through the body (hormones)

Concept 5.4Proteins have many structures, resulting in a wide range of functions

hereditary information

H,RI 0

,c -c,;H/ I "oH

H

Amino acid monomer (20 types)

Pho,phate 9• Enzymes• Structural protein s, Storage proteins, Transport proteins• Hormones

1 • Receptor protein s, Motor proteins

• Defensive proteins i=

, Catalyze chemical reactions, Provide structural support, Store amino acids, Tra nsport substances, Coordinate organismal responses• Receive signals from outside cell, Fu nction in cell movement• Protect against disease

Concept 5.5Nucleic acids store and ti:ansmit Nitrogenous base DNA: (]..... o:·...o;:::.6 ,• Sugar = dcoxyriboscStores all hereditary information

group 1 • Nitrogenous bases

C, G. A, T

®-- CH2 0

Nucleotide monomer

• Usually double-stranded

RNA : .,,-,,-• Sugar = ribose, Nitrogenous bases = C, G, A, U, Usually single-stranded

Carries protein -codinginstructions from DNA to protein synthesizi ng machinery

Copyright © 200B Pearson Education. Inc.. publishing as Pearson Benjamin Cummings.


Chapter 8: An Introduction to


I Chapter 8: An Introduction to Metabolism

Concept 8.1 An organism's metabolism transforms matter and energy, subject to the laws of thermodynamics

1. Define metabolism.

2. There are two types of reactions in metabolic pathways: anabolic and catabolic.

a. Which reactions release energy?

b. Which reactions consume energy?

c. Which reactions build up larger molecules?

d. Which reactions break down molecules?

e. Which reactions are considered "uphill"?

f. What type of reaction is photosynthesis?

g. What type of reaction is cellular respiration?

h. Which reactions require enzymes to catalyze reactions?

3. Contrast kinetic energy with potential energy.

4. Which type of energy does water behind a dam have? A mole of glucose?

Concept 8.2 Thefree-energy change of a reaction tells us whether the reaction occurs spontaneously

5. What is/ree energy? What is its symbol?




6. For an exergonic reaction, is G negative or positive?

7. ls cellular respiration an endergonic or an exergonic reaction? What is G for this reaction?

8. ls photosynthesis endergonic or exergonic? What is the energy source that drives it?

9. To summarize, if energy is released, G must be what?

Concept 8.3 ATP powers cellular work by coupling exergonic reactions to endergonic reactions

10. List the three main kinds of work that a cell does. Give an example of each.

(1)

(2)

(3)

11. Here is a molecule of ATP. Label it. Use an arrow to show which bond is likely to break.

0 0 0

-o-PII -O-PII -O- II

o1 - oI - oI

-

---

OH OH




a. By what process will that bond break?

b. Explain the name ATP by listing all the molecules that make it up.

12. When the terminal phosphate bond is broken, a molecule of inorganic phosphate P i is formed, and energy is ?

For this reaction: ATP "'7 ADP + Pi, G = ------------

ls this reaction endergonic or exergonic?

FYI: An essay question on the 2009 AP Biology exam asked students to identify the molecules that make up ATP. What are they again?

13. What is energy coupling?

In many cellular reactions, a phosphate group is transfen-ed from ATP to some other molecule in order to make the second molecule less stable. The second molecule is said to be--------

14. Look for this amazing bit of trivia: Ifyou could not regenerate ATP by phosphorylating ADP, how much ATP would you need to consume each day?

Concept 8.4 Enzymes speed up metabolic reactions by lowering energy barriers

15. What is a catalyst?

,




16. What is activation energy (EA)?

On the graph, label the x-axis "Progress of the reaction" and the y-axis "Free Energy." Label EA on this sketch, both with and without enzyme.

t

a. What effect does an enzyme have on EA?

b. Label tiG. ls it positive or negative?

c. How is tiG affected by the enzyme?

17. Label this figure while you define each of the following terms:

enzyme

substrate

active site

products




18. What is meant by inducedfit? How is it shown in this figure?

19. Explain how protein structure is involved in enzyme specificity .

20. Enzymes use a variety of mechanisms to lower activation energy. Describe four of these mechanisms .

(1)

(2)

(3)

(4)

21. Many factors can affect the rate of enzyme action. Explain each factor listed here.

a. initial concentration of substrate

b. pH

c. temperature

22. Recall that enzymes are globular proteins. Why can extremes of pH or very high temperatures affect enzyme activity?

23. Name a human enzyme that functions well in pH 2. Where is it found?

24. Distinguish between cofactors and coenzymes. Give examples of each.

25. Compare and contrast competitive inhibitors and noncompetitive inhibitors. Label each type of inhibitor in this figure.

',

....,_,-Initial substrate(threonine)

lsoleuclneused up by cell

Intermediate A

-Active site of enzyme 1 no

longer binds Intermediate Bi!eli me,z--0·=·=

threonine; pathway is switched off.i,En 'me a:- '

....,...lsoleuclne binds to allosteric site

Intermediate Ci1§!!.Yme,4!

Intermediate D

i• n yme'.r

d7 J(isoleucine)

End product




Concept 8.5 Regulation of enzyme activity helps control metabolism

26. What is allosteric regulation?

27. How is it somewhat like noncompetitive inhibition? How might it be different?

28. Explain the difference between an allosteric activator and an allosteric inhibitor.

29. Although it is not an enzyme, hemoglobin shows cooperativity in binding 02. Explain how hemoglobin works at the gills of a fish.

30. Study this figure from your book (Figure 8.22).

a. What is the substrate molecule to initiate this metabolic pathway?

b. What is the inhibitor molecule?

c. What type of inhibitor is it?

d. When does it have the most significant regulatory effect?

e. What is this type of metabolic control called?





1. --2.-

-

3. --

4. -- 5.- --6.- --

i chapter 2: the chemical context of life -...

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