Exam 1

Question 1

What are the seven characteristics of life?

Answer 1

1. growth and development
2. order
3. homeostasis
4. reproduction
5. sense and respond
6. obtain and use energy
7. evolution

Question 2

Identify the different steps in the process of science

Answer 2

Observe, question, hypothesis, experiment, analyze results, record data/results

Question 3

What is a controlled experiment?

Answer 3

experiences no experimental manipulation. Serves as a basis of comparison.

Question 4

Identify dependent and independent variable

Answer 4

dependent: what you measure, what’s being changed
independent: what you change, manipulated

Question 5

What is a theory?

Answer 5

a hypothesis that has never been disproved, even after many years of rigorous testing

Question 6

How does sample size affect your data?

Answer 6

The larger the sample size, the more likely the results will have statistical significance

Question 7

What does it mean when data is determined to be statistically significant?

Answer 7

a measure of confidence that the results are not due to random change

Question 8

Have a basic understanding of the culture of science

Answer 8

Scientists build on what has been learned from earlier research
o Pay close attention to contemporary scientists working on the same problem
Cooperation and competition characterize the scientific culture
o Scientists check the conclusions of others by attempting to repeat experiments
o Scientists are generally skeptics

Question 9

What is the purpose of peer review?

Answer 9

The scientific community helps ensure the accuracy of science

Question 10

what ways do scientists ensure the accuracy of science?

Answer 10

• Working together
• Checking each other’s work
• Helping to inspire new ideas
• Catching cases of bias and fraud
• Motivating excellence with recognition

Question 11

Have a clear understanding of atomic structure. Where are protons, neutrons, and electrons located?

Answer 11

• the nucleus is the dense core of the atom
• protons: found in nucleus
• neutrons: found in nucleus
• electrons: found on outside

Question 12

how do you calculate mass number of an atom?

Answer 12

protons + # neutrons

Question 13

What classifies an element as an isotope?

Answer 13

Isotopes are the alternate mass forms of an element. They have the same number of protons and elections, but differ in their number of neutrons

Question 14

Be able to fill orbital shells and have a clear understanding of what is the valence shell and valence electrons.

Answer 14

Valence shell: outermost shell

8 fill each additional shell, 2 fill the first shell

Question 15

What are three types of chemical bonds we discussed in class. Which is the strongest and the weakest

Answer 15

Ionic
Covalent (STRONGEST)
Hydrogen bonds (WEAKEST)

Question 16

What are the criteria for a hydrogen bond to form?

Answer 16

whenever a positively charged H held in one molecule by a covalent bond close to a negatively charged atom-typically an oxygen or nitrogen-belonging to another molecule

Question 17

You must understand what kind of compounds each bond holds together

Answer 17

Compounds are either a molecule (covalent bond) or a salt (ionic bond)
Covalent bonds: SHARED Ionic bonds: donate or gain electrons

Question 18

What is the meaning of polar covalent? How does the polar nature of the water molecule allow it to dissolve substances?

Answer 18

Polar covalent are shared electrons
There are two hydrogen atoms that attract to one oxygen atom. The hydrogen atoms are positively charged and the oxygen is negative, making it polar. It dissolves substances because when another polar substance is there, the particles will separate the particles making it dissolve. Salt is one thing if mixed with water that dissolves.

Question 19

What is an organic molecule?

Answer 19

Molecules with chains of carbon atoms (generally used of yerm in this class= products of lift forms)

Question 20

What are the 4 macromolecules of the cell? What are the building blocks (monomers) and functions of these macromolecules?

Answer 20

• Carbohydrates (function in energy storage and structural support)
• lipids
• nucleic acids
• proteins

Question 21

What is a polymer? Are macromolecules polymers?

Answer 21

Monomers linked together in a chain, Yes

Question 22

What are the monomers of DNA? What is the structure of these monomers?

Answer 22

Nucleotides,
Adenine (A) (double ring)
Thymine (T) (single ring)
Guanine (G) (double ring)
Cytosine (C) (single ring)
Hydrogen bonds between C-G or A-T base pairs form the ladder “rungs”

Question 23

What is the structure of an amino acid?

Answer 23

All have the same basic core structure, but each also has a unique chemical side group. Side groups vary in size (bulky v small), and charge (+, neutral, -)

Question 24

What is the R group of an amino acid?

Answer 24

The radical group, the variable part of the amino acid, also called the side group. Size and charge vary in side groups

Question 25

What is the function of the plasma membrane?

Answer 25

(cell membrane): form physical barrier, allow transport (importation of raw material and exportation of..)

Question 26

What is the difference between cytoplasm and cytosol?

Answer 26

Cytoplasm: contains water inside cell (cytosol) and formed structures inside cell (proteins, sugars, lipids, nucleic acids, etc.) Organelles are composed in cytoplasm

Question 27

Identify the different components of the cell membrane

Answer 27

Phospholipids Membrane proteins (integral and peripheral proteins/transport and signaling) Carbohydrate groups (attached to proteins^) Cholesterol

Question 28

What organelles are found plants but not animals?

Answer 28

Water Vacuole, chloroplast, cellulose cell wall

Question 29

What organelles and structures make up the endomembrane system

Answer 29

includes the nuclear membrane (nucleus), rough ER, golgi (packages), lysosomes (engulf), and vacuoles

Question 30

What are cytosolic, integral and peripheral proteins

Answer 30

``` Cytosolic proteins: free floating proteins in cytosol Integral proteins: integrated or embedded within/ transport proteins Peripheral proteins (signaling proteins): don’t transport, function in cell signaling. They can’t function without carbohydrate groups. They function in energy storage and structural support, linked to proteins or lipids ```

Question 31

What are the constituents of the cell membrane? What characteristics of of one of the constituents give the membrane its semi- permeable feature?

Answer 31

Densely-packed hydrophobic phospholipid tails prevent macromolecules and smaller charged particles (like ions) from wandering across membranes Only SMALL, UNCHARGED molecules can diffuse through the bilayer directly (ie. CO2, O2) The Cell membrane is made up of phospholipid bilayer that has proteins throughout. The cell is semi permeable bc of the hydrophobic tails of the phospholipid. Bc charged particles require water to move across, they can’t get through by bilayer bc it’s hydrophobic.

Question 32

What are the types of membrane transport? What are the examples of specific molecules that cross the membrane by each method of transport*****

Answer 32

Glucose transport | Active transport

Question 33

What are the characteristics of transport proteins? What specific examples of transport proteins were identified in lecture?

Answer 33

They are very specific (ion channels only move ions) and some require energy and some don’t There are glucose transporters: movement of glucose into a cell, and then extract energy form glucose bc need energy. High concentration in the fluid before moves down gradient into cell. aquapore transporters (transport protein moving only water across) active transport: REQUIRE energy by which molecules are needed at higher concentration on one side (not at equilibrium) Large or hydrophilic molecules are pumped from an area or lower concentration to higher concentration with help of transport proteins and ATP energy o moving against gradient: so obv need energy, ATP Anything involving active transport ONLY uses ATP there is pumps: transport proteins use pumps to move proteins against gradient Some require energy and some don’t (another characteristic)

Question 34

What is diffusion?

Answer 34

the movement of molecules and ions from areas of high concentration to areas of low concentration

Question 35

What factors affect the rate of diffusion?

Answer 35

1. Concentration gradient 2. Temperature 3. Particle size and chemical structure 4. size

Question 36

What is concentration gradient

Answer 36

When you can see a clear difference of two particles in two regions, clear difference of concentration

Question 37

Have a clear understanding of the function of the na/k pump and the na/glucose co transporter

Answer 37

Glucose transporter: movement of glucose into a cell, and then extract energy form glucose bc need energy. High concentration in the fluid before moves down gradient into cell. - If increase concentration of glucose in blood, the cells can clear glucose into bloodstream when being prompted by hormone insulin. When reset to normal blood glucose levels, it is called Homeostasis. - Glucose uses the transporter to move across bc it’s too big The Na/K pump provides one of the best examples of active transport. It moves Na ions from inside the cell (low concentration) to outside (high concentration) the cell and K ions in the opposite direction. In both cases the movements of the ions are against their respective concentration gradients. Energy is required for this work which is usually supplied by ATP - Sodium ions will move outside the cell - K will always want to move in, inside the cell (high concentration) and outside (low concentration)

Question 38

how do you calculate atomic number of an atom?

Answer 38

electrons or protons an atom contains. number at the top of the element, carbon is 6