Chapter 2 Molecular Biology ⚛

Particles that are found in the atomic nucleus are:
Protons and electrons
Protons, neutrons and electrons
Protons and neutrons
Neutrons and electrons

Protons and neutrons

An element is defined by the number of:
Electrons
Protons
Chemical bonds
Ions
Neutrons

Protons

What does the atomic number represent?
number of neutrons
total number of protons and neutrons
total number of electrons and protons combined
number of protons
total number of electrons, protons, and neutrons

number of protons

If only one type of atom makes up a substance, what can you call this substance?
a neutron
a compound
a proton
an element

an element

Which of the following has a positive charge and a mass of one amu?
proton
electron
element
neutron

proton

The space around the nucleus where the electrons are most likely to be found

What is an electron shell?
A hard container holding electrons close to the nucleus
The space around the nucleus where the electrons are most likely to be found
The electron's protective outer layer
The exact location of an electron

2

What is the maximum number of electrons that can occupy the 2s orbital?
8
2
3
6

Electrons are considered valence electrons if they are in the outermost electron shell.

Which of the following statements is true?

Electrons removed from atoms always increase the stability of the atom.

The energy of electrons decreases with increasing distance from the nucleus.

Electrons circle the nucleus in predictable orbits like the Earth around the sun.

Electrons are considered valence electrons if they are in the outermost electron shell.

8

If Argon is a noble gas and its atomic number is 18, how many electrons can be found in the valence level?
18
6
36
8

Strontium

Given the following information, which element(s) are most likely to lose electrons?
I. Iodine is a member of Group VII (halides).
II. Strontium is located in the second column of the periodic table.
III. Selenium has six valence electrons.
Selenium
Iodine
Selenium and strontium
Strontium

ionic, covalent, polar covalent, metallic

What are the types of chemical bonds?

an attraction between two atoms due to one transferring an electron(s) to the other. They (MOST OF THE TIME, NOT ALL OF THE TIME) form between metal and non metal atoms.

What is an ionic bond

an attraction between two atoms due to the sharing of electrons between them. MOSTLY form when two atoms have seven electrons in the outer shell and share the eighth. Mostly form between two non metal atoms.

What is a covalent bond

a covalent bond in which the shared electrons are more attracted to one atom than the other and move closer to that atom. Makes one negative and the other positive

What is a polar covalent bond?

A metallic bond is formed between metal atoms because electrons are free to move inside of metals. Making them SUPER STRONG

What is a metallic bond

A material containing sets of two or more atoms connected together by chemical bonds

What is the definition of a chemical?
A material containing sets of two or more atoms connected together by chemical bonds
A material containing only non-metals
A material containing sets of two or more molecules connected together by chemical bonds
A material containing ionic bonds only

Electrostatic attraction

What force causes a chemical bond to hold atoms together?
Electrostatic attraction
Glue
Nuclear forces
Gravitational attraction

Polar ionic bond

Which of the following is NOT a type of chemical bond?
Ionic bond
Polar covalent bond
Covalent bond
Polar ionic bond

Ionic

A bond is formed between a sodium atom and a chlorine atom when the sodium atom gives an electron to the chlorine atom. Identify the type of bond formed between sodium and chlorine.
Covalent
Ionic
Metallic
Polar covalent

Covalent

Which of the following type of bond normally forms between two non-metal atoms?
Covalent
Metallic
Ionic
Plastic

mixtures of solvent and solute

Solutions

the substance that dissolves other substances in it

Solvent

substances that are dissolved in solvent

Solutes

maximum amount of a solute that will dissolve in a particular solvent at a specific temperature and pressure

Solubility

the spread of molecules from areas of high to low concentration

Diffusion

a solution with less than a the maximum amount of solute

Unsaturated Solution

a solution where the solvent has dissolved all the solute it can maxiumum

Saturated Solution

solution where there is more dissolved solute than the maximum, way past equilibrium

Supersaturated Solution

thin slices of material that contain tiny holes and let solvent molecules through

Semipermeable Cell Membranes are?

the migration of solvent molecules across a semipermeable membrane

Osmosis

the amount of external pressure needed to equalize the two solutions

Osmoitic Pressure

a solution that has the same concentration solute as a given solution (good balance, will not cause swelling or shrinking)

Isotonic Solution

a solution with lower concentration of solute than a given solution (may cause swelling)

Hypotonic Solution

a solution with a higher concentration of solute than a given solution (may cause shrinking)

Hypertonic (note ER)

Osmosis

what is the process of water moving across a semipermeable membrane?
Osmosis
Saturation
Solubility
Diffusion

It would shrivel up

What would you expect to happen to a piece of celery you put into a hypertonic solution?
It would crack in half
It would shrivel up
It would stay the same
It would swell

Solute molecules will move across semipermeable membranes to equalize concentration on both sides of the membrane

Which of the following is NOT true?
Molecules will try to move so that there is equilibrium of concentration in all parts of a solution

Diffusion and osmosis are important in biological systems

You can have more solute in a solution than can be found in a saturated solution of the same components at equilibrium

Solute molecules will move across semipermeable membranes to equalize concentration on both sides of the membrane

The crystal would cause the excess sugar to come out of the supersaturated solution and crystallize.

What would happen if you added a sugar crystal to a supersaturated solution of sugar in water?
The crystal would cause the excess sugar to come out of the supersaturated solution and crystallize.
The sugar crystal would settle on the bottom of the container the solution was in.
Nothing; no change.
The sugar crystal would dissolve in the solution

Salt dissolving in water without stirring

Which of the following is an example of diffusion?
Cells exploding in a hypotonic solution
Sodium moving to an area of higher concentration across a cell membrane
Precipitation of a solid from a solution
Salt dissolving in water without stirring

92%

Approximately what percentage of the blood is water?
0%
60%
92%
34%

Because we've come to suspect that water is an important requirement for the development of life

Why are we attempting to find water elsewhere in our solar system?
We aren't; the fact that water is vital to life on Earth is just an amazing coincidence
Because we're running out on Earth
Because we want to prove that Earth is unique by showing water doesn't exist anywhere else
Because we've come to suspect that water is an important requirement for the development of life

Two hydrogen, one oxygen

What atoms make up a water molecule?
Two hydrogen, one oxygen
One hydrogen, one oxygen
Two oxygen, one hydrogen
Two hydrogen, three oxygen

Because it allows the transport of nutrients to and within cells

Why is water important to human cell life?
Because it allows the transport of nutrients to and within cells
Because it allows the transport of nutrients within cells (but not between them)
Because it gives the cell its shape
Because it provides energy

Provide energy (sugar)

Which of the following is NOT a use of water in the human body?
Chemical reactions
Temperature regulation
Provide energy (sugar)
Transport

is a compound containing molecules each of which is made up of two atoms of hydrogen and one atom of oxygen bonded together

Water

Cell life
Transport
Chemical reactions
Temperature regulation
Waste excretion

Why is water important to human bology?

Is based on the fact that cells have water inside them

Cell life

How oxygen and food make it through our bodies, and how blood flows through the veins and arteries to take those nutrients to where they're needed

Transport

an important solvent and a major part of a lot of chemical reactions that happen inside the cells of our bodies

Chemical reactions

water has a high heat capacity, meaning it takes a lot of energy to change its temperature

Body temperature

We remove them through urine which is mostly water

Excretion of waste