Ch. 2 & 3 Questions-

Front 1

What distinguishes one element from another

Back 1

The number of protons

Front 2

Describe the formation of an ionic bond

Back 2

An ionic bond forms through the electrical force between oppositely charged ions

Front 3

What is the difference between ionic and covalent bonds?

Back 3

Ionic bonds are formed when electrons are transferred between atoms.

Covalent bonds are formed when valence electrons are shared between atoms

Front 4

How does a molecule differ from an atom?

Back 4

A molecule is a bunch of atoms combined

An atom is the smallest part of an element you can get without splitting the nucleus of an atom

Front 5

How do polar molecules form hydrogen bonds?

Back 5

Opposite charges of polar molecules can interact to form hydrogen bonds

Front 6

What determines whether a compound will dissolve or mix with water?

Back 6

It is dependent upon the solute and the solvent. The solvent is the substance that is present in the greatest amount, it dissolves the solutes.

Front 7

How do polar molecules differ from non polar molecules? How does this difference affect their interactions?

Back 7

Polar molecules dissolve in water because the attraction between the water molecules and solute molecules is greater. (ex:sugar/water-dissolve) Non polar molecules do not have charged regions & are not attracted to polar molecules (ex: oil/water-does not dissolve)

It effects whether they dissolve or not

Front 8

Describe an example of cohesion or adhesion that you might observe in your daily life.

Back 8

Cohension - water beads on a recently washed car. (Molecules of substances sticking together)

Adhesion - dip one end of a paper towel in a glass of water and watch the water climb up the fibers of the paper towel getting it wet above the level of the water in the glass.

(Molecules attract to a different substance)

Front 9

How do acids and bases differ in terms of the concentration of H+ ions and OH- ions?

Back 9

?

Front 10

How does water help maintain a consistent temperature in living things and in aquatic and humid environments?

Back 10

?

Front 11

What is the relationship between a polymer and a monomer?

Back 11

Each subunit in a complete molecule is called a monomer.

Monomers that are linked together form molecules called polymers

Front 12

Explain how both nucleic acids and proteins are polymers. Be sure to describe the monomers that make up the polymers.

Back 12

Nucleic acids are polymers made up of monomers called nucleotides.

Proteins are a polymer made up of monomers called amino acids.

Front 13

How are carbohydrates and lipids similar? How are they different?

Back 13

They are both made of Carbon, Hydrogen and Oxygen.

Carbohydrates provide a source of usable chemical energy for cells.

Some Lipids are broken down as a source of usable energy for cells but some cannot be and are part of the cell's structure.

Front 14

How does the properties of carbon atoms result in the large variety of carbon based molecules in living things?

Back 14

Each carbon atom has four unpaired electrons in its outer energy level. Therefore, carbon atoms can form covalent bonds with up to four other atoms, including carbon atoms. There are 3 structures in carbon-based molecules (straight chains, branched chains & rings). All can form and bond together.

Front 15

Hydrogen peroxide breaks down into water and oxygen. Explain why this is a chemical reaction. What are the reactants and the products in the reaction?

Back 15

It is a chemical reaction because it is not possible to rearrange water and oxygen to form Hydrogen Peroxide after they are split apart.

Reactants are the substances changed during a chemical reaction. (Ex: Hydrogen Peroxide)

Products are the substances made by the chemical reaction (Ex: Water and Oxygen)

Front 16

How do endothermic and exothermic reactions differ?

Back 16

Endothermic reactions absorbs more energy than it releases.

Exothermic reactions release more energy than it absorbs.

Front 17

In an exothermic reaction, what must be true about the energy involved in the reaction(is more energy absorbed or released?)

Back 17

More energy is released.

Front 18

What is activation energy?

Back 18

It is the amount of energy that needs to be absorbed for a chemical reaction to start. (ex:like pushing a rock up a hill)

Front 19

How does a catalyst affect the activation energy of a chemical reaction?

Back 19

A catalyst is a substance that decreases the activation energy needed to start a chemical reaction, as a result it also increases the rate of the chemical reaction.

Front 20

Describe how enzymes alter the rate of a chemical reaction.

Back 20

Enzymes are catalysts and therefore lower the activation energy and increase the rate of chemical reaction.

Front 21

How does extreme temperature and pH alter the active site of an enzyme and its ability to function?

Back 21

They can affect the shape and function or activity of an enzyme. At only slightly higher temperatures, hydrogen bonds in an enzyme can break apart and lose the ability to function.

Front 22

What characteristics are shared by most cells?

Back 22

They tend to be microscopic in size and have similar building blocks. They are enclosed by a membrane (cell membrane) that controls the movement of materials into and out of the cell.

Front 23

What are the functions of the cytoskeleton?

Back 23

The cytoskeleton supports and shapes the cell.

Front 24

Describe the role of the Nucleus and Nucleolus.

Back 24

Nucleus-is the storehouse for most of the genetic information, or DNA in our cells.

Nucleolus-The dense region within the Nucleus where tiny organelles essential for making proteins are assembled.

Front 25

What function does the cell wall perform for plant cells?

Back 25

The cell wall shapes and supports individual cells and entire organisms. Cell walls of plants have openings or channels to allow water or molecules small enough to freely pass through.

Front 26

Outline the pathway for production of proteins starting from the DNA in the nucleus.

Back 26

?

Front 27

Why do phospholipids form a double layer in water?

Back 27

Because the membrane touches the cytoplasm inside the cell and the watery fluid outside the cell, the properties of polar heads and non polar tails cause the phospholipids to arrange themselves in layers, like a sandwich

Front 28

Explain how membrane receptors transmit messages across the cell membrane.

Back 28

Membrane receptors molecules that cannot enter the cell wall. When bound it changes the receptor transmits the signal inside the cell by changing shape

Front 29

What is the location and function of cholesterol in the cell membrane?

Back 29

Cholesterol is located between the fatty acid chains.

Cholesterol molecules strengthen the cell membrane and make it remain relatively fluid

Front 30

Where are carbohydrates located in the membrane and what is there function?

Back 30

Carbohydrates are found on the outside of the cell membrane

Carbohydrates attached to membrane proteins serve as identification tags, enabling cells to distinguish one type of cell from another

Front 31

How do intracellular receptors differ from membrane receptors?

Back 31

Intracellular receptors are molecules that may cross the cell membrane and bind within or inside the cell.

Membrane receptors are molecules that cannot cross the cell membrane. They bind to a signal molecule outside the cell.

Front 32

Describe the similarities between enzymes and receptors.

Back 32

?

Front 33

How do cells use diffusion to obtain needed nutrients and eliminate wastes?

Back 33

?

Front 34

What is the difference between simple diffusion and facilitated diffusion?

Back 34

?

Front 35

Explain why the cell must use facilitated diffusion to obtain some nutrients?

Back 35

?

Front 36

You observe a cell sitting in a solution and notice that it is getting smaller due to water diffusing out of the cell. Is the solution the cell is in hypertonic, hypotonic, or isotonic compared to the cell?

Back 36

Hypertonic

Front 37

How do transport proteins that are pumps differ from those that are channels?

Back 37

Transport proteins that are pumps move materials against a concentration gradient.

Transport proteins that are channels allow materials to diffuse into and out of a cell down a concentration gradient.

Front 38

How do endocytosis and exocytosis differ from diffusion?

Back 38

Diffusion does not require energy input from the cell as endo and exo do

Front 39

A cell needs to move Na+ ions against its' concentration gradient (from low to high concentration). What type of transport, facilitated diffusion or active transport, would the cell use to do this?

Back 39

Active Transport