Molecular Biology Quiz LUOA

Carbohydrates can be found in what major forms? Choose all that apply.

sugars fiber starch

Products

the ending material in a reaction

Chemical reaction

the making and breaking of chemical bonds to form or rearrange molecules

Reactants

the starting material in a reaction

The polar nature of water and the hydrogen bonds it can form contribute to what properties of water? Choose all that apply.

Cohesion and adhesion Expanding when frozen Excellent solvent The ability to moderate temperature High surface tension

Starch and Glycogen are examples of what kind of carbohydrates?

Complex carbohydrate

Cellulose is a long chain of glucose molecules linked in such a way that they are typically undigestible. It is the major component in the plant cell wall and provides strength and structure to plants. Under what term(s) can cellulose be classified? Choose all that apply.

Complex carbohydrate Polysaccharide Fiber

What kind of bond is characterized by the sharing of electrons?

Covalent

_________ forms a double helix.

DNA

Mass is the amount of ___________ in a substance.

matter

Element name

nihonium

Amino acids in proteins are composed of which molecular groups? Choose all that apply.

r-group amino group Carboxylic acid group

A neutral atom must have:

same number of protons and electrons

Which items are matter? Choose all that apply.

-Atoms -Water -Bricks

Number of electrons in a neutral atom of this element

113

Number of protons

113

atomic number

113

Number of neutrons

173

How many different amino acids are there?

20

atomic mass

286

Describe the basic structure of a phospholipid and how this structure affects the arrangement of phospholipids in a membrane. Using your best grammar, write 3-5 sentences.

A phosphate group is joined to a glycerol head with two fatty acid tails to form phospholipids. The two fatty acid tails are uncharged and hydrophobic, while the phosphate group at the head of the molecule is negatively charged and hydrophilic. The phosphate heads have hydrophilic (attraction to water) tendencies because of their negative charges. As a result, the heads face aqueous regions, such as the inside and exterior of a cell. However, because they repel water, the tail portions of phospholipids are incapable of interacting with an aqueous environment. As a result, the tails are towards the bilayer's interior. A bilayer or cell membrane is held together by the hydrophobic tails' positive interactions with one another.

What is an enzyme? Choose all that apply.

A protein that decreases the activation energy needed for a particular reaction A catalyst for biochemical reactions A protein that catalyzes the reaction of specific substrates

If a solution has a pH of 12, it is considered what?

A strong base

What is the basic unit, or monomer, for proteins?

Amino acids

Describe and discuss the amino acids. Include information on what they are, their structure, and how many there are. Using your best grammar, write 3-5 sentences.

Amino acids are monomers or repeating units that make up protein chains. An amino group, a carboxylic acid group, and a special side chain known as an R-group make up all amino acids. There are 21 different types of amino acids needed for life. Only the R-groups, which give each type of amino acid unique features, distinguish the 21 amino acids from one another. Charged (+ or -) side chains, polar uncharged side chains, hydrophobic side chains, and special cases (which really don't have a consistent quality) are the four divisions into which the properties of amino acids can be divided.

Lipids are primarily composed of what elements?

Carbon and hydrogen

What are some functions of proteins? Choose all that apply.

As enzymes As hormones As signals and receptors For structure As antibodies

Using your best grammar, describe how the periodic table of elements is arranged. Use 2-4 complete sentences.

Beginning with hydrogen, which has one proton and an atomic number of 1, the elements are listed in the periodic table in sequence of increasing atomic number. The table has a total of 18 vertical columns and 7 horizontal rows. The rows are referred to as "periods," while the columns are called "groups."

How does an enzyme increase the rate of a biochemical reaction?

By decreasing the activation energy requirement

Which of the following is not a molecule?

He

In your own words, discuss the importance of enzymes within a living system and include what the function of an enzyme is. Using your best grammar, write 2-4 sentences.

In a biological system, enzymes serve as a catalyst by speeding up biochemical reactions and allowing for further use because they do not undergo permanent change. Enzymes are important because they are responsible for nearly all reactions in a living system.

Which saccharides are considered simple carbohydrates?

Monosaccharides and disaccharides

Enzymes are important for what reactions in a living system?

Nearly all

Element symbol

Nh

The majority of enzymes are what kind of macromolecule?

Proteins

The number of which subatomic particle identifies an atom as a particular element?

Proton

The nucleus of an atom is made up of which subatomic particles?

Protons and neutrons

What is significant about the R-group of an amino acid?

R-groups are unique to each amino acid.

The starting material in a chemical reaction is called what?

Reactants

What is the substrate in a reaction?

Reactants that an enzyme can act on

The pH of a solution describes what?

The concentration of H+ ions

In your own words, describe what a buffer is and why it is important. Write 3-5 sentences using your best grammar.

There must be a means to maintain pH levels of solutions stable despite any changes in environmental conditions so that the pH within the body of a living organism stays within a specific range. Buffers allow for this. A buffer is used to maintain a solution's steady and constant pH. Even when an acid, a base, or more water is added to a buffered solution, the pH doesn't vary noticeably.

What is the function of steroids? Choose the best answer.

They have many functions, including as endocrine signals.

The outer most electrons in an atom are called what?

Valence electrons

In your own words, describe the octet rule and how this is related to the formation of chemical bonds. Use your best grammar to write 2-4 sentences.

With the exception of elements whose valence shell is the initial energy level, which can only retain 2 electrons, most elements are most stable when they have 8 electrons in their valence shell. As a result, the majority of atoms strive to have eight electrons (or two for the first energy level) in their outer shell.

Endergonic

a chemical reaction that absorbs energy

Exergonic

a chemical reaction that releases energy

If a solution has a high concentration of H+, it is what?

acidic

A molecule is formed when two or more atoms ___________ together.

bond

A __________ is a substance that keeps the pH of a solution relatively constant and is highly stable.

buffer