Chapter 2 Holt McDougal Biology Biology Review Chapter 2 Holt McDougal Biology

Question 1 A substance composed of only 1 type of atom is called what? A) a cell B) a nucleus C) a molecule D) an element .

Answer 1 D- Element

Q 2 T or F: Enzymes are specific for specific substrates. .

A 2 TRUE

Q 3 3) List the 2 types of Nucleic Acids

A 3 DNA & RNA

Q 4 4) True or False: “Nonpolar molecules have no negative or positive poles.

A 4 TRUE

Q 5 5) An enzyme or catalyst does what to the reaction rate? A) speeds it up B) Slows it down C) has no effect

A 5 A- speeds it up.

Q 6 6) A __________________molecule has a slightly positive end and a slightly negative end.

A 6 6) A ___POLAR_____molecule has a slightly positive end and a slightly negative end.

Q 7 7) List some conditions that affect the function of enzymes?

A 7 Temperature, pH, amount of substrate

Q 8 8) What is meant by saying that an enzyme is DENATURED? What might cause this?

A 8 - this means the enzyme is destroyed. Caused by high temperatures. 8) What is meant by saying that an enzyme is DENATURED? What might cause this? - this means the enzyme is destroyed. Caused by high temperatures.

Q 9 9) How do enzymes work to speed up a reaction?

A 9 Enzymes LOWER the ACTIVATION ENERGY needed to start the reaction.

Q 10 10) T or F: “An Enzyme is not used up when catalyzing a reaction.”

A 10 True

Q 11 11) The molecule on which an enzyme acts is called a(n) ____________.

A 11 11) The molecule on which an enzyme acts is called a(n) substrate

Q 12 12) The portion of an enzyme molecule into which a specific substrate can fit is called the _________________________.

A 12 12) The portion of an enzyme molecule into which a specific substrate can fit is called the active site

Q 13 13) Are lipids (fats) polar or nonpolar?

A 13 Nonpolar

Q 14 14) In a solution, the substances are ________________. A) Evenly distributed B) unevenly distributed

A 14 A) Evenly distributed

Q 15 15) When sugar is dissolved in water, the water acts as the _____________. A) Solute B) Solvent C) Ion

A 15 B) Solvent

Q 16 16) Long chains of __________ ____________ form the building blocks of proteins.

A 16 16) Long chains of amino acids_ form the building blocks of proteins.

Q 17 17) Are sugars considered a Carbohydrate, Protein, Lipid, or Nucleic Acid?

A 17 Sugars are a carbohydrate.

Q 18 18) _______solutions have a pH of less than 7.

A 18 18) Acidic solutions have a pH of less than 7.

Q 19 19) The pH scale ranges from ____ to ______.

A 19 19) The pH scale ranges from __0__ to 14

Q 20 20) All organic compounds contain what element?

A 20 CARBON

Q 21 21) T or F: “Carbohydrates, lipids, and nucleic acids are all organic macromolecules.”

A 21 TRUE

Q 22 22) Why don’t oil & water mix when placed in the same container?

A 22 Water is polar & oil is nonpolar so they don’t mix.

Q 23 23) The bond formed when 2 atoms SHARE a pair of electrons is called a(n) __________bond.

A 23 23) The bond formed when 2 atoms SHARE a pair of electrons is called a(n) covalent bond

Q 24 24) A molecule with a partial positive charge on one side & partial negative charge on the other side such as water said to be a ___________________molecule.

A 24 24) A molecule with a partial positive charge on one side & partial negative charge on the other side such as water said to be a POLAR molecule.

Q 25 _________bonds form between molecules that have opposite charges. A) Ionic B) Covalent C) hydrogen

A 25 A) Ionic

Q 26 26) Is starch a lipid, carbohydrate, or protein?

A 26 carbohydrate

Q 27 27) A substance with a pH greater than 7 is _____________. A) Acidic B) Basic C) Neutral

A 27 B) Basic

Q 28 28) Long chains of nucleotides make up _________________. A) Amino Acids B) Nucleic Acids C) Protiens D) Lipids E) Carbohydrates

A 28 B) Nucleic Acids

Q 29 29) Weak chemical attractions between polar molecules of water are __________bonds. A) Hydrogen B) Nuceleotide C) Peptide D) Ionic

A 29 A) Hydrogen

Q 30 30) The attraction between like water molecules to other water molecules is called __________________.

A 30 30) The attraction between like water molecules to other water molecules is called cohesion

Q31 31) The attraction of water molecules to different molecules is called ____________.

A 31 31) The attraction of water molecules to different molecules is called Adhesion.

Q 32 (25) What is an element?

A 32 (25) Element = a pure substance composed of only 1 type of atom.

Q 33 (26) 26 (1) ______are typically liquids called oils at room temp.

A 33 (1) U (unsaturated fats) are typically liquids called oils at room temp.

Q 34 2) ______are typically solids at room temp.

A 34 2) saturated fats are typically solids at room temp Amino Acids

Q 35 _____typically come from animal sources and are less healthy to consume.

A 35 3) Saturated fats typically come from animal sources and are less healthy to consume.

Q 36 4) ______typically come from plant sources & are considered “more healthy” to consume.

A 36 4) UNSATURATED FATS typically come from plant sources & are considered “more healthy” to consume.

Q 37 5) ________have only single bonds (NO DOUBLE BONDS) and therefore have the maximum number of hydrogens possible for the molecule.

A 37 5) saturated fats have only single bonds (NO DOUBLE BONDS) and therefore have the maximum number of hydrogens possible for the molecule.

Q 38 6) _______contain double bonds so they have fewer hydrogens.

A 38 6) Unsaturated fats contain double bonds so they have fewer hydrogens.

Q 39 Which reaction pathway most likely occurred in the presence of a catalyst or enzyme? How do you know?

A 39 Which reaction pathway most likely occurred in the presence of a catalyst or enzyme? How do you know? -reaction 2 (because the line is lower on the graph, so it takes less activation energy to start the reaction).

Q 40 The difference between the 2 paths shown is due to a difference in the _________ _______ needed to start each reaction.

A 40 The difference between the 2 paths shown is due to a difference in the activation energy needed to start each reaction.

Q 41 (bonus question) Which of the following conditions affects the function of enzymes? A) Concentration B) Heat C) pH D) All of the above E) None of the above

A 41 D) All of above

Q 42 (Bonus) ________, such as glucose, are a source of energy, and are used as structural materials in organisms. A) Carbohydrates B) Proteins C) Lipids D) Nucleic Acids

A 42 A) Carbohydrates

Q 43 (BONUS) ___________are nonpolar molecules that store energy & are an important part of cell membranes. A) Carbohydrates B) Protiens C) Lipids D) Nucleic Acids

A 43 C-Lipids