AP bio test #1

Describe a feature of organic compounds not found in inorganic compounds?

Carbon atoms covalently bonded to each other

How can you tell the difference between the saturated and unsaturated fatty acids by looking at molecular structures?

Saturated fatty acids are solid at room temperature. The absence of carbon-carbon double bonds allows the molecules to pack closely together.

Why would a hydrogen atom from a water molecule be attracted to the nitrogen atom in ammonia?

The nitrogen has a partial negative charge, and the hydrogen attached to the oxygen has a partial positive charge.

What are some ways to distinguish DNA from RNA?

- the nitrogenous bases - sugars

Bacteriophages are viruses that infect bacteria by injecting them with

-DNA

What element would be available for plants in soil, that would not be available in saw dust (cellulose)

-Nitrogen

Describe the structures of carbohydrates.

-They occur as monomers, chains of monomers (polymers), and branched -Made up of carbon, hydrogen, and oxygen (ratio is 1:2:1)

What is produced as a byproduct during the formation of protein or carbohydrate polymers?

-Water

Describe the formation of a peptide bond.

A covalent bond is formed between a carbon atom and a nitrogen atom along with the formation of H2O.

How do molecules released by fish in an aquarium become nutrients for an aquatic plant?

Ammonia molecules released by the fish are converted by bacteria to nitrates, which are used by plants to make proteins and nucleic acids.

How do the properties of water at an air-water interface enable an insect to walk on the water's surface?

Hydrogen bonds between molecules at the surface of the water provide surface tension, which allows the water surface to deform but not break under the insect.

What is responsible for the cohesive property of water?

Hydrogen bonds between the oxygen atom of one water molecule and a hydrogen atom of another water molecule.

How are polypeptide chains broken down?

Hydrolysis reaction (add a water molecule to break it down)

What is the most directly responsible for water's unique properties?

It forms hydrogen bonds (because of its polarity)

Describe the effect of a greater number of cysteine amino acids on the stability of proteins?

It leads to increased protein stability because of an increased number of S-S (sulfur) bonds in the tertiary structure of a protein.\

If an amino acid is deleted from an amino acid chain, how will it affect the structure of the protein?

It will affect primary, secondary, tertiary structures of the protein.

Which biological compound carries the genetic code?

Nucleic acids

The carbohydrates glucose, galactose, and fructose (C6 H12O6) have the same chemical formula, but different structural formulas. How does this affect their properties?

The carbohydrates have different properties because they have different arrangements of carbon, hydrogen, and oxygen atoms.

Describe how amino acids affect the tertiary structure of a protein.

The interactions of the different R-groups with other R-groups and with their environment determine the tertiary structure of the protein.

How do heterotrophs obtain the carbon necessary for building biological molecules?

They eat plants or other animals that eat plants, break down the molecules to obtain carbon and other atoms, and rearrange them into new carbon-containing molecules.