Biology chapter 6 Review

Chapter 6 Chemistry in Biology Objectives and Review

• Section 1 Vocabulary: atom (Proton, neutron, electron), element, isotope, compound, covalent bond, molecule, ion, ionic bond, Vander Waals forces (9 words).

Section 1 1. What is an ion? A charged atom, it has lost or gained electrons 2. How do Ionic bonds form? by transfering electrons between ions 3. A covalent bond forms between two atoms that _share __ electrons to form a molecule4. An atom with more electrons than protons has a _negative __ charge.5. What does it mean for a molecule or atom to be polar? It has positive and negative areas of the molecule, due to unequal sharing of electrons. 6. What information is given in a chemical formula? _number and names of atoms in the reaction _-Does a chemical formula tell you the kind of bonds or arrangement of the atoms? _no7. Where in a molecule is energy stored? Chemical bonds 8. Two atoms with the same number of protons but different numbers of neutrons are called what? isotopes 9. Draw a carbon atom and show the arrangement of the electrons• Why is carbon the atom of “life”? It can make 4 strong covalent bonds, close to the

nucleus _10. What elements make up the majority of living things ? CHNOPS 11. What is an isotope? A form of an element with a different mass number because it has

extra neutrons 12. How can isotopes be used to calculate the age of fossils? The radioactive form usually decays at a constant rate that can be measured . Like carbon 14 13. How many electrons fit into the first energy level ? 2 the second? __8_-

• Section 2 Vocabulary: chemical reaction (reactants, products), activation energy, catalyst, enzyme, substrate, active site. ( 6 words)

• SC.912.L.18.11 Explain the role of enzymes as catalysts that lower the activation energy of biochemical reactions. Identify factors, such as pH and temperature, and their effect on enzyme activity.

1. Write the chemical reaction for respiration C6H12O6 + 6O2 --- 6CO2 + 6 H20_2. Circle the reactants and box the products in the above reaction. First are reactants on the right are products 3. In a balanced equation, How many molecules of glucose are used in this reaction? 1, • How many molecules of oxygen are used? 6• How many molecules of Carbon Dioxide are produced? 6 How many molecules of

Water are produced? 64. What is activation energy? The energy needed to start a reaction5. Factors that might affect the rate of an enzyme catalyzed reaction include what? temperature, amount of product, reactant, enzymes or pH

6. What does changing the pH do to an enzyme? It can change its shape and cause it to lose its active site 7. Changing the temperature? It can change its shape and cause it to lose its active site

8. The major role of an enzyme in biochemical reactions is what? to lower the activation energy which will most often increase the rate of the reaction

9. What is the active site of an enzyme? The place where the substrate fits into the enzyme

10. Draw a graph of an enzyme catalyzed reaction and a reaction without an enzyme: 11. What happens to chemical bonds in chemical reactions? They are broken and formed 12. Why must chemical reactions be balanced? You can’t create or destroy matter

Why can’t this be correct? H2 + O2 --> H2O there are 2 oxygens on the reactant side and only one on the product side 13. True or false? During a chemical reaction, the enzyme is used up and more must be created before the reaction can occur again. Explain. False, enzymes are not used up in reactions they catalyze 14. What is the difference between exothermic and endothermic reactions? Exothermic give off heat, endo take it in

• Section 3 vocabulary: polar molecules, hydrogen bond, mixture, solvent, solute, acids, bases, pH, buffers. ( 9 words)

• SC.912.L.18.12 Discuss the special properties of water that contribute to Earth's suitability as an environment for life: cohesive behavior, ability to moderate temperature, expansion upon freezing, and versatility as a solvent. (MC AA)

• List the reasons why each property is important to life. see page 162 • 1. cohesive behavior: ability to flow, capillary action, transport nutrients,• 2. ability to moderate temperature: helps maintain homeostasis, keeps temperatures

constant due to hydrogen bonds• 3. expansion upon freezing: allows life under frozen bodies of water, density changes

mix nutrients• 4. versatility as a solvent: transport of nutrients and ions 5. Because of water’s chemical structure, the molecule is polar_ allowing it to mix with and be a solvent to all things that are _polar_. (Polar or non polar?)6. What is it about water’s chemical makeup that makes it have these properties? Because it is a polar molecule and has polar covalent bonds , it forms hydrogen bonds that cause most of these properties.

7. Relate the shape of a water molecule to the distribution of electrons. The unequal sharing of the electrons and placement of the electrons cause the shape

8. What are the two parts of a solution? A solvent and a solute In a sugar solution, sugar is the solute? What is the water? The solvent

9. Draw the pH scale. Label acid, base, and neutral. Give an example of each. 0 to 14 with acid from 0 to 7, 7 neutral above 7 basic. Water is 7, lemom juice acid,

bleach is basic

Section 4

• Section 4 vocabulary: organic chemistry, macromolecules, polymers, carbohydrates, lipids, protein, amino acids, nucleic acids, nucleotides. (9 words)

SC.912.P.8.12 Describe the properties of the carbon atom that make the diversity of carbon compounds possible.1. How many electrons does Carbon have in the valence shell 4 Draw a carbon atoms valence electrons2. How many covalent bonds does this allow it to form? 43. Are the bonds close to the nucleus or far from it? close

4. Does this make them stronger or weaker than ones that are further from the nucleus? stronger

SC. 912.L.18.1 Describe the basic molecular structure and primary function of the four major classes of biological macromolecules. What are organic compounds? Those that contain carbon___List the 4 major types of organic molecules and a brief description of each.1. Carbohydrates: CH2O energy, Mono, di, Poly2. Lipids: C and H no ratio, long term storage of energy, membranes3. Proteins: made of amino acids, enzymes, structures, longer energy storage than carbs4. Nucleic Acids: Sugar Phosphate and nitrogen base, DNA and RNA genetic information

5. Amino acids in a chain can interact to form sheets or coil into more complex shapes. Why is the shape of a complex protein important? It may be an enzyme and have an active site or be a structure In an organism. 6. What property of lipids makes them the perfect component of the cell membrane? Hydrophobic/ nonpolar water barrier. 7. What are the basic building blocks of proteins? Amino acids 8. Unlike carbohydrates and fats, proteins contain nitrogen.9. These organic molecules act as enzymes or structural components like collagen that is found in skin, tendons and bones. proteins

10. Which type of organic molecule has primary, secondary, tertiary and quaternary structures? Proteins 11. Where are phospholipids found? Cell membranes, 12. What is the function of nucleic acids? store and transmit genetic information13. What are the three parts of a nucleotide? Sugar, phosphate and nitrogen base.

SC.912.L.18.2 Describe the important structural characteristics of monosaccharides, disaccharides, and polysaccharides and explain the functions of carbohydrates in living things.1. As you move from mono to di to poly saccharides what happens to the amount of energy the molecule holds? It increases. So what happens to the function of these types of molecules? They become more long term storage or structural molecules rather than quick energy sources. 2. What is the structure of a fatty acid? Long hydrocarbon chains3. What are some of the functions they perform? _long term energy storage , insulation

Extra review questions

• SC.912.L.18.4 Describe the structures of proteins and amino acids. Explain the functions of proteins in living organisms. Identify some reactions that amino acids undergo. Relate the structure and function of enzymes.

• 1. How does the shape of a protein play a role in the function it performs? The shape is important to the role as an enzyme and the ability to accept the substrate into the active site to lower the activation energy.

1. What is an ion? An atom that gains or loses one or more electrons

2. Ionic bonds form between oppositely charged atoms.

3. A covalent bond forms between two atoms that _share___ electrons to form a molecule

4. Adhesion is an attraction between different substances_

5. An atom with more electrons than protons has a _negative_ charge.

6. __polar__molecules dissolve well in water.7. ___DNA__stores hereditary information that

can be used to make proteins.8. The ability of __water__to retain heat helps

cells maintain homeostasis.9. A nucleotide has ____3__ parts. What are

they? _sugar, phosphate, nitrogen base__10. When cells break down food, the energy from

the food is temporarily stored as __ATP_

11._ENZYMES_ speed up a chemical reaction by _LOWERING_the activation energy of the reaction

12. The amount of energy needed to cause a chemical reaction to start is called_ACTIVATION ENERGY_.

13. Without enzymes, chemical reactions necessary for life _WOULD NOT__occur at a rate sufficient to sustain life.

14. When an enzyme binds with its substrate, the activation energy needed for the chemical reaction to occur is _LOWERED_

15. Where are the electrons of an atom found? IN ELECTRON CLOUDS AROUND THE NUCLEUS

16. What stores heredity information?_DNA_17. Which is true about an enzyme? a. is not used

up when catalyzing a reaction. b. lowers the activation energy of a reaction. c. bonds with a substrate molecule at the enzyme’s active site. d. All of the above

18. Where is the energy in the ATP molecule? BETWEEN THE PHOSPHATE BONDS_

19. What is the shape of DNA ? _DOUBLE HELIX_20. What is a substrate? _THE MOLECULE ON

WHICH THE ENZYME ACTS__ 21. Examples of unsaturated fats are _OILS, SOFT

MARGARINES_22. What does the type and sequence of amino

acids determine about a protein? THE SHAPE OF THE PROTEIN_

23. Define atom. _The smallest particle of matter that can retain the chemical properties

24. Define element A substance that is composed of only one type of atom

25. What does it mean to be polar? A molecule that has a partial

positive charge on one side and a partial negative charge on the other side

26. Does a chemical formula tell you the kind of bonds or

arrangement of the atoms? No 27. Is water polar or non polar? polar 28. Where in a molecule is energy stored? In the chemical bonds

29. What is glycogen? Animal form of carbohydrate storage

30. What is the pH scale? 1-14 7 is neutral 1-6

acid, 8-14 base 31. What type of organic molecule is a sugar?

carbohydrate_ 32. What are the two types of nucleic acids? Rna

dna

33. What are proteins made up of? AMINO ACIDS34. List some examples of lipids. WAX, OIL,

CHOLESTEROL 35. What are lipids made up of? GLYCEROL AND

FATTY ACID CHAINS CARBON AND HYDROGEN

. Glucose and fructose, with the formula C6H12O6, differ in _____.a. numbers of atomsb. arrangement of atomsc. kinds of atomsd. arrangement of electrons

What element has the ability to form 4 strong covalent bonds in straight chains, branched chains, or rings making it the element of life?a. Sodiumb. Carbonc. Oxygend. Hydrogen

How many electrons does Carbon have in the valence shell and how many covalent bonds does this allow it to form?a. 4/2b. 6/6c. 4/4d. 2/2

Fatty acids, triglycerides, phospholipids, and steroids are examples of what type of organic molecule?a. lipidsb. proteinsc. carbohydratesd. nucleic acids

An organic compound with a ratio of about two hydrogen atoms and one oxygen atom for each carbon atom is a(n) ____________________.a. lipidb. proteinc. carbohydrated. fatty acid

• Organic compounds that serve as storehouses of energy, such

as starch and structural support such as cellulose are known as a. monosaccharidesb. lipidsc. proteinsd. polysaccharides

What are the basic building blocks of proteins?a. nucleic acidsb. peptide bondsc. amino acidsd. glycerol and fatty acids

These organic molecules contain large numbers of chemical bonds and therefore contain large amounts of stored energy They are used for insulation, energy storage and part of the cell membrane structure. a. lipidsb. proteinsc. carbohydratesd. nucleic acids

What property of lipids makes them the perfect component of the cell membrane?a. many chemical bondsb. non polarc. polard. organic

Simple sugars used as quick sources of energy such as glucose and fructose are examples ofa. monosaccharidesb. disaccharidesc. starchesd. polysaccharides

Unlike carbohydrates and fats, proteins contain _____.a. nitrogenb. carbonc. hydrogend. oxygen

These organic molecules act as enzymes or structural components like collagen that is found in skin, tendons and bones.a. lipidsb. proteinsc. carbohydratesd. nucleic acids

The energy needed to start a chemical reaction is calleda. activation energyb. start up energyc. ADPd. glucose

Which type of organic molecule has primary, secondary, tertiary and quaternary structures?a. lipidsb. proteinsc. carbohydratesd. nucleic acids

Because of water’s chemical structure, the molecule is _______ allowing it to mix with and be a solvent to all things that are __________.a. polar, polarb. polar, non polarc. non polar, polar d. non polar, non polar

The major role of an enzyme in biochemical reactions is a. to make the reaction go fasterb. to make the reaction go slowerc. to lower the activation energyd. to raise the activation energy

Factors that might affect the rate of an enzyme catalyzed reaction includea. temperatureb. pHc. concentrations of reactants and productsd. all of the above

Water molecules are attracted to each other in a property called what?

a. cohesionb. adhesionc. expansiond. capillary action

Due to water’s chemical structure, it takes ___________ to increase its temperature.a. a large amount of energyb. a small amount of energy

Amino acids in a chain can interact to form sheets or coil into more complex shapes. Why is the shape of a complex protein important?a. It may contain the active site of an enzymeb. It determines if the protein is a carbohydrate or notc. It helps the protein fit into the cell membrane properlyd. The shape determines if it is a lipid or a protein

The special properties of this substance that contribute to Earth's suitability as an environment for life are: cohesive behavior, ability to moderate temperature, expansion upon freezing, and versatility as a solvent. To what substance is this sentence referring?a. carbonb. glucosec. oxygend. water