Biology module 5 study guide
Which of the following is a carbohydrate? a. NH3 b. CO2. c. C2H4O d. C5H10O5 e. C3H8O3
Only D
Identify each of the following as an atom, element, or molecule: A. H2CO3 B. Nitrogen-14 C. P
a. Molecule, b. Atom, c. Element
How many atoms (total) are in a molecule of C3H8O? What atoms are present and how many of each atom?
12 total; 3 carbon, 8 hydrogen, 1 oxygen
How many electrons are in an atom that has 32 protons?
32 electroms
What is the chemical equation for photosynthesis? What 4 things are necessary for a plant to carry out photosynthesis?
6 CO2 + 6 H2O ➡️ C6H12O6 + 6 O2 CO2, H2O, energy from sunlight, and a catalyst like chlorophyll
What are the enzymes, and for what purpose are they usually used?
A special class of proteins that are used as catalysts.
Consider the following chemical reaction: N2 + 3H2 ➡️ 2NH3 A. What are the reactants? B. What are the products? C. How many molecules of H2 are used in the reaction?
A. N2 and H2 B. NH3 C. Three
What are the basic building blocks proteins, lipids, and polysaccharides?
Amino acids
What is the difference between an element and an atom?
An element contains all atoms that have the same number of protons (and therefore the same number of electrons), regardless of the number of neutrons. An atom is a single entity, determined by it's number of protons, electrons, *and* neutrons.
What is the "lock and key" theory of enzyme action?
An enzyme has an active site that is shaped especially for the molecule that it must work on. The action that the enzyme takes cannot happen until the molecule attaches to that active site.
How does DNA store information?
As a sequence of nucleotide bases
What kind of reaction is used for building disaccharides, polysaccharides, fats, and proteins? What kind of reaction can break these substances down?
Dehydration reactions build them up. Hydrolysis reactions break them down.
If you add energy to the molecules of a liquid, will it turn into a gas or a solid?
Gas
What holds the two belies in a DNA molecule together?
Hydrogen bonds
Describe where the protons, neutrons, and electrons are in an atom.
In an atom, protons and neutrons cluster together at the center, which is called the nucleus. Electrons orbit around the nucleus.
Other than using a catalyst, how can a reaction be sped up?
Increasing temperature
A chemist wants to study diffusion. Should a semipermeable membrane be used?
No
If two proteins contain the same type and number of amino acids, but the order in which they are linked up is different, are the properties of the two proteins the same?
No
Two solutions of different solute concentration are separated by a membrane. After a while, the water levels of the two solutions change. Has osmosis or diffusion taken place? What kind of membrane is being used?
Osmosis, which requires a semipermeable membrane.
What determines the vast majority of characteristics in an atom?
The number of electrons (or protons) in an atom
Describe the pH scale and what it measures.
The pH scale measures the acidity (lower than 7) or alkalinity (higher than 7) of a solution. On this scale, 7 is neutral.
What does the number after an atom's name signify?
The sum of the protons and neutrons in the atom's nucleus
Which of the following is an acid? (Pictures are shown labelled a, b, and c)
c
What are the basic parts of a nucleotide?
phosphate group, sugar, base
