12th bio unit 1 exam

the backbone of DNA contains deoxyribose, whereas the backbone of RNA contains ribose

DNA and RNA are nucleic acids that can store bio info based on the sequence of their nucleotide monomers. Which of the following best describes the structural difference btwn DNA and RNA

hydrogen bonds form btwn the oxygen atom of one molecule and the hydrogen atom of another hydrogen is positive and oxygen is negative. opposites attract

Describe why hydrogen bonds form btwn water molecules

The change leads to increased protein stability bcs of an increased number of bonds in the tertiary structure of the proteins

Researchers compared similar proteins from related organisms in different habitats. They found that the proteins from organisms living in harsh environments had a greater number of cysteine amino acids than did proteins from organisms not living in harsh environments. The structure of cysteine is shown below. Bonds can form btwn the sulfur atom and dif cysteine amino acids. Which of the following best describes the effect of a greater number of cysteine amino acids on the stability of proteins.

a lake can be 4° while outside temp can be 0°. Water will freeze and less dense ice will float to the top, leaving warmer liquid water at the bottom. Ice at top acts as insulation for water at the bottom, keeping it from freezing. SO homies can survive during the winter.

The arrangement of the water molecules in ice causes the ice to float. Explain how ice floating on the surface of a body of water affects the water in a way that is beneficial to the organisms in it

The carbs have different properties bcs they each have a single carbon oxygen double bond

The carbs glucose, galactose, and fructose have the same chemical formula but different structural formulas, as represented in the figure below. Which of the following statements about glucose, galactose, and fructose is most likely true?

hydrogen bonds btwn molecules at the surface of the water provide surface tension, which allows the water surface to deform but not break under the insect

The figure below is a diagram of water molecules at the air-water interface at the surface of a pond. How would you best describes how the properties of water at an air-water interface enable an insect to walk on the water's surface?

it will affect the primary, secondary, and tertiary structures of the CFTR proteins

The protein CFTR is made up of 1480 amino acids linked together in a chain. Some humans produce a version of the CFTR protein in which phenylalanine (an amino acid) has been deleted from position 508 of the amino acid chain. Which of the following best predicts how the amino acid deletion will affect the structure of the CFTR protein?

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

Water and ammonia interact to form hydrogen bonds, as represented in the figure to the right. Which statement best explains the formation of hydrogen bonds represented in the figure?

The formation of a covalent peptide bond in a dehydration synthesis reaction

Which of the following is an accurate description of the process shown?

carbon atoms covalently bonded to each other

a feature of organic compounds NOT found in inorganic compounds is the presence of

at 40 mm Hg partial pressure, myoglobin has a greater affinity for oxygen than hemoglobin has

both myoglobin and hemoglobin are proteins that bind reversibly w molecular oxygen. The graph shows the oxygen-binding saturation of each protein at different concentrations of oxygen. Which statement is correct?

as water temp decreases, hydrogen bonds spread out which changes the volume. Water molecules are more spread out in ice than in liquid water. same mass, different volume

explain why the arrangement of water molecules is different in ice and water

smaller units: enzymes are macromolecules and are MADE OF amino acids. parts of enzyme: active site that substrate fits into. Connected by peptide bonds job of enzyme: speeds up chem reactions. ex. catalase is produced to get rid of the H2O2 that naturally occurs in cells.

many biostructures are composed of smaller units assembled into more complex structures having fns based on their structural organization. For the complex structure of enzymes, describe the smaller units, their assembly into larger structure, and one major fn of these larger, organized structures

sugars/monosaccharides

monomer of carbohydrates

not actually made of monomers

monomer of lipids

nucleotides

monomer of nucleic acids

amino acids

monomer of proteins

water

the synthesis of protein or carbohydrate polymers always produces which of the following as a byproduct?

arrows to the left and right

to explain surface tension, use a single water molecule and draw arrows representing the possible locations of hydrogen bonds formed by the molecule.

the sun

we get free energy mainly from

The interactions of the different r-groups with other r-groupsand with their environment determine the tertiary structure of the protein

which of the following best describes how amino acids affect the tertiary structure of a protein?

They occur as monomers, chains of monomers, and branched structures

which of the following best describes the structures of carbs

it forms hydrogen bonds

which of the following is most directly responsible for water's unique properties

Hydrogen bonds btwn the oxygen atoms of one water molecule and a hydrogen atom of another water molecule

which of the following is responsible for the cohesive property of water?

nucleic acids

which of the following is used to carry the genetic code?