Exam 1 Study Guide

Question 1

Similarities Between Eukaryotes and Prokaryotes

Answer 1

• They both have DNA and have a Membrane

Question 2

classify what organisms fall into the two domains (eukaryote, prokaryote)

Answer 2

• Prokaryote- single-celled microorganisms, bacteria (singular, bacterium) and archaea (singular, archaean)
• Eukaryote- All other forms of life, including plants and animals

Question 3

What is a nucleotide is and classify the 4 DNA nucleic acids and their base pair

Answer 3

• Nucleotide- Each chain is made up of four kinds of chemical building blocks
• 4 DNA nucleic acids- A,T,C,G
• 4 DNA nucleic acid bases: a&t , c&g

Question 4

Positive Feedback Regulation and Examples

Answer 4

which an end product speeds up its own production. ( less common)
The clotting of your blood in response to injury

Question 5

Negative Feedback Regulation and Examples

Answer 5

a loop in which the response reduces the initial stimulus ( more common)
insulin signaling

Question 6

Understand evolutionary relationships if given a phylogenetic tree

Answer 6

A branching diagram that represents a hypothesis about the evolutionary history of a group of organisms.

Question 7

Understand the four postulates (observation presented by Darwin)

Answer 7

• 1. Population with varied inherited traits
• 2. Elimination of individuals with certain traits that make them more visible
• 3. Reproduction of survivors
• 4. Increased frequency of traits that enhance survival

Question 8

Understand the process of the scientific method and the sequential order of the steps

Answer 8

• Observation
• Question
• Hypothesis
• Test with experiment
• Analyze data
• Report finding

Question 9

Identify and explain the 4 properties of water

Answer 9

• cohesive behavior- Collectively, the hydrogen bonds hold the substance together
• ability to moderate temperature- Water moderates air temperature by absorbing heat from air that is warmer and releasing stored heat to air that is cooler. Water is effective as a heat bank because it can absorb or release a relatively large amount of heat with only a slight change in its own temperature.
• expansion upon freezing- While other materials contract and become denser when they solidify, water expands. The cause of this exotic behavior is, once again, hydrogen bonding
• versatility as a solvent- Even molecules as large as proteins can dissolve in water if they have ionic and polar regions on their surface. Many different kinds of polar compounds are dissolved (along with ions) in the water of such biological fluids as blood, the sap of plants, and the liquid within all cells

Question 10

Be able to distinguish between compound, elements, and molecules. Also understand there differences/similarities if any.

Answer 10

• Compound- a combination of elements
• Elements- chemical compounds in pure form
• Molecules - a group of atoms bonded together, representing the smallest fundamental unit of a chemical compound that can take part in a chemical reaction.

Question 11

Understand the characteristics of the subatomic particles (protons, neutrons, electrons)

Answer 11

• Protons- positive charge, in nucleus
• Neutrons- no charge, in nucleus
• Electrons- electron, forms a negative cloud around the nucleus

Question 12

Be able to calculate the number of protons, neutrons and electrons if asked

Answer 12

• Atomic # - # of protons
• Mass # - the sum of protons plus neutrons
• Atomic # - # of electron in a neutral atom

Question 13

Identify the order of biological hierarchy (largest to smallest)

Answer 13

• Biosphere- all life on earth
• Ecosystems- all living things in an area and non living things
• Communities- living things inhabiting a particular area
• Populations- all members that live in a defined area
• Organisms- individual living things
• Organs- body part is made up of multiple tissues and has a specific function
• Tissues- group of cells that work together to provide a specialized function
• Cells- life fundamental unit of structure and function
• Organelles- functional components found in cells
• Molecules- the smallest level of organization

Question 14

Octet Rule and be able to determine when an atom is stable

Answer 14

• refers to the tendency of atoms to prefer to have eight electrons in the valence shell.
• The number of protons match the number of neutrons

Question 15

Understand the characteristics of hydrogen bonding. Also identify molecules/compounds that are hydrophilic or hydrophobic

Answer 15

• Forms when a hydrogen atom covalently bonded to a more electronegative atom and is also attracted to another electronegative atom
• Hydrophilic- cotton
• Hydrophobic- vegetable oil

Question 16

Understand why certain atoms have more electron density than others in a polar molecule

Answer 16

the electrons are shared unequally, as one atom exerts a stronger force of attraction on the electrons than the other. The one that has a stronger force of attraction has a partial negative charge.

Question 17

Understand the properties and forces that hold water molecules together or different molecules to a different surface (cohesion, adhesion, surface tension)

Answer 17

Cohesion- the electrons are shared unequally, as one atom exerts a stronger force of attraction on the electrons than the other.

Adhesion- The clinging of one substance to another, such as water to plant cell walls, in this case by means of hydrogen bonds.

Surface tension- A measure of how difficult it is to stretch or break the surface of a liquid. Water has a high surface tension because of the hydrogen bonding of surface molecules.

Question 18

Identify the solvent and solute in a solution

Answer 18

• solvent - is the chemical that is present in the greatest amount and, therefore, is the substance in which each of the remaining chemicals are distributed or dissolved.
• Solute- is a chemical that present in a lesser amount, relative to the solvent, and must be uniformly distributed throughout the solution.

Question 19

Identify strong acids and bases via a chemical reaction equation

Answer 19

• Strong acids- substance that increases the hydrogen ion concentration of a solution. Having more h+ than OH-
• Strong Bases- A substance that reduces the hydrogen ion concentration of a solution having more OH- than H+

Question 20

Be able to calculate [H+] or [OH-] concentration

Answer 20

• pH= -log(H+)

Question 21

Understand what a buffer solution is

Answer 21

is a substance that minimizes changes in the concentrations of and in a solution.

Question 22

Understand the characteristics of organic chemistry. What compound does organic chemistry focus on?

Answer 22

the study of compounds that contain carbon

Question 23

Identify the characteristics of carbon

Answer 23

• Carbon has 6 electrons, with 2 in the first electron shell and 4 in the second shell; thus, it has 4 valence electrons in a shell that can hold up to 8 electrons
• carbon usually forms single or double covalent bonds. Each carbon atom acts as an intersection point from which a molecule can branch off in as many as four directions.

Question 24

Understand the bonding properties of valence electrons, how many valence electrons does carbon, oxygen, hydrogen have?

Answer 24

• Carbon- 4 valence electrons, forms covalent bonds with up to four other atoms
• Oxygen – 6 valence electrons, The oxygen forms two single covalent bonds with the two hydrogen atoms.
• Hydrogen – 1 valence electrons, hat forms a special type of dipole-dipole attraction when a hydrogen atom bonded to a strongly electronegative atom exists in the vicinity of another electronegative atom with a lone pair of electrons

Question 25

Understand the different isomers

Answer 25

- Cis- trans isomers- have the same covalent bonds but differ in their spatial arrangements - Enantiomers - are isomers that are mirror images of each other and that differ in shape due to the presence of an asymmetric carbon, one that is attached to four different atoms or groups of atoms.

Question 26

Understand the 4 types of chemical bonds and be able to provide an example of each

Answer 26

- covalent bond - involves the sharing of electrons between two atoms equally, ex: carbon dioxide - polar bond- A covalent bond between atoms that differ in electronegativity. The shared electrons are pulled closer to the more electronegative atom, making it slightly negative and the other atom slightly positive. - Hydrogen bond- A type of weak chemical bond that is formed when the slightly positive hydrogen atom of a polar covalent bond in one molecule is attracted to the slightly negative atom of a polar covalent bond in another molecule or in another region of the same molecule. - Ionic bond- A chemical bond resulting from the attraction between oppositely charged ions.