Biology Chapter 3

One reason carbon is an excellent element to form the basis of life on Earth is that each carbon can bond with what number of other atoms?

4

What is a neutral pH?

7

Order the following from the highest concentration of free hydrogen ions to the lowest. Alkaseltzer with a pH of 8-10. Human blood with a pH of 7.4. Alkaseltzer with a pH of 8-10.Human blood with a pH of 7.4.A solution of HCl with a pH of 2.

Alkaseltzer with a pH of 8-10.Human blood with a pH of 7.4.A solution of HCl with a pH of 2. Human blood with a pH of 7.4. Alkaseltzer with a pH of 8-10.

Computers and books are excellent ways to store information in the modern age. However, without electricity, computers are useless and books are prone to decomposition over time. Certain biomolecules are extremely stable on a geologic time scale and have been preserved for millennia. Thus, some scientists are preparing to encode and store modern information in which biomolecule?

DNA

What 2 things store genetic information, which is the code of life.

DNA and RNA

In attempting to generate the ingredients for life, Stanley Miller mixed gases together and added an electrical spark. Why was the spark required? (may be multiple correct answers) Electrical current provides the energy required to forge covalent bonds. Electrical storms were common on early Earth. Electrical current helps generate ionic bonds. Creating covalent bonds takes a lot of energy.

Electrical current provides the energy required to forge covalent bonds. Creating covalent bonds takes a lot of energy.

One way to preserve food is to store it in an acidic environment to prevent the growth of harmful bacteria. One day, you decide to make pickles (fermented cucumbers). After placing the cucumbers in water, you realize you don't have any vinegar to add. You search the kitchen for something to use as a replacement. Other than being safe to eat, which of the following characteristics would your substitute vinegar need to have? It would need to donate plenty of H+ ions. It would need to be hydrophilic. It would need to have a high pH. It would need to be polar. It would need to be hydrophobic. It would need to accept plenty of H+ ions.

It would need to donate plenty of H+ ions. It would need to be hydrophilic. It would need to have a high pH.

Egg whites solidify in the presence of acids. Would lemon juice (pH 2.3) or orange juice (pH 3.5) be better for solidifying egg whites? Why?

Lemon juice, because it donates more H+ ions than orange juice.

It takes a large input of energy to cause water to evaporate. Why is evaporating water so energy intensive?

The hydrogen bonds need to be broken

When you add a base to an acidic solution, what happens to the solution? (may be multiple correct answers) The pH increases. The pH decreases. The solution becomes less acidic. The solution becomes more acidic.

The pH increases. The solution becomes less acidic.

How do carbon-based molecules form the basis of life as we know it

They can form a diversity of long chains, branches, and ringed molecules and can form both polar and non-polar molecules.

True or False: Hydrogen bonds between strands of DNA allow the DNA strands to separate for replication or transcription and also allow the strands to re-anneal more easily than covalent bonds.

True

Order the following from the lowest concentration of free hydrogen ions to the highest. Milk with a pH of 6.5. Washing soda with a pH of 8-10. A solution of H2SO4 with a pH of 2.

Washing soda with a pH of 8-10. Milk with a pH of 6.5. A solution of H2SO4 with a pH of 2.

To which of the following atoms can a hydrogen atom bond? a partially positively charged hydrogen a partially negatively charged nitrogen a partially negatively charged oxygen a partially positively charged carbon

a partially negatively charged nitrogen a partially negatively charged oxygen

Match the type of bond to its description. a. covalent b. hydrogen c. ionic 1. Atoms that share electrons. 2. A partially positively charged hydrogen atom bound to a partially negatively charged atom. 3. Attraction of a negatively charged atom or molecule with a positively charged one.

a- 1 b- 2 c- 3

Match the monomer to the polymeric macromolecule that it can form. a. nucleotide b. monosaccharide c. amino acid 1. carbohydrate 2. DNA and RNA 3. proteins

a- 2 b- 1 c- 3

Based on what you've learned about what happens when water freezes, which of the following helps explain why road salt is added in the winter to help prevent ice from forming on roadways and sidewalks? a. Salt causes the water molecules to vibrate and heat up. b. Since salt is polar, it dissolves in water and disrupts hydrogen bonding. c. Salt disrupts the crystal lattice by getting between the hydrogen molecules. d. Salt generates covalent bonds with water and prevents freezing.

b c

Which of the following are acidic and which are basic? ammonia baking soda tomatoes oranges lemons seawater

basic: seawater ammonia baking soda acidic: tomatoes oranges lemons

Which of the following compounds are organic? carbohydrate water nitrogen gas protein

carbohydrate protein

what provides structure and serves as a means of energy storage.

carbohydrates

Order the levels of protein structure from simplest to most complex. chain folded into 3D shape two or more proteins joined together chain folded into coils and sheets chain of amino acids

chain of amino acids chain folded into coils and sheets chain folded into 3D shape two or more proteins joined together

What type of bonds are the bonds between simple sugar molecules in a carbohydrate?

covalent

Order the following types of bonds from strongest to weakest. ionic covalent hydrogen

covalent ionic hydrogen

Order the following states of water from fewest to most hydrogen bonds formed. gas liquid solid

gas liquid solid

what is the minimum number of genes required for life?

hundreds

Water molecules display a significant amount of cohesion (to each other) and adhesion (to other objects). This is part of what allows the formation of dense water droplets on the surface of leaves or other objects or animals. Additionally, these properties create surface tension on the surface of water, which can allow insects such as water striders to "walk" on water. These unique properties of water are due to which type of bonding?

hydrogen

An acid is a molecule that donates which of the following in a solution of water? hydrogen ions neutrons protons electrons

hydrogen ions protons

Phospholipids have hydrophilic phosphate heads. Their long fatty acid tails of hydrocarbons do not mix in water. What term describes this characteristic of the fatty acid tails?

hydrophobic

Which of the following are hydrophilic? ions NaClCorrect polar molecules non-polar molecules

ions NaClCorrect polar molecules

Classify each molecule as a lipid or carbohydrate according to its organic molecule type. triglyceride starch phospholipid cholesterol cellulose

lipid: phospholipid, cholesterol, triglyceride carbohydrate: starch, cellulose

Jeffrey Bada, Harold Urey, and Stanley Miller have been able to create which of the following types of molecules in their experiments? monomers biomolecules polymers amino acids

monomers amino acids

What is the constituent monomer of carbohydrates?

monosaccharides

Put the following pH values in order of hydrogen ion concentration from the highest H+ concentration to the lowest. pH 7 pH 1 pH 12 pH 3

pH 1 pH 3 pH 7 pH 12

Amino acids are linked together by covalent bonds to make which polymer?

proteins

True or False: One reason carbon is an excellent element to form the basis of life is the fact that it can form extremely long chains.

true