Biology Test #1

1.     Differentiate between inductive and deductive reasoning.

Inductive- a form of logical thinking that uses related observations to arrive at a general conclusion

  Ex) see a bunch of dogs & all of them have hair, can come up with general principle that every dog has hair

Deductive- uses a general principle or law to forecast specific results

  Ex) all mammals that exist have hair, see a bird that with no hair but feathers therefore it is not a mammal

2.     Given an experimental procedure, identify if the experiment is a controlled experiment.  Also, be able to identify the experimental group, control group, independent variable, dependent variable, and constant variables.

Controlled experiment- all variables except for the one being tested (independent) are kept constant

Experimental group- group that differs from only one key factor; altered group

Control group- group that experimental group is compared to; unaltered group (normal)

Independent variable- variable that is different between groups

Dependent variable- changes because of independent variable (result)

Constant variables- all other variables that are identical between the two groups

3.     Given a specific isotope of an element, identify the number of protons, neutrons, electrons, and valence electrons

Bromine-85   (just changes the atomic mass)

Protons= 35

Neutrons= 50

Electrons= 35

Valence electrons= 7

4.     For any main group element, predict the most probable charge (number and sign) of an ion.  Classify the ion as an anion or cation.

Anion- negatively charged ion (gain of electrons)

Cation- positively charged ion (loss of electrons)

Nitrogen: charge=negative and magnitude=2

5.     Predict the bond that will form between any two elements. (ionic, polar-covalent, or non-polar covalent).

Ionic bond- forms between ions with opposite charges (Na + Cl Na+ and Cl-)

Polar-covalent bond- unequal sharing of the electrons (O-H, N-H, S-H)

Non-polar covalent bond- equal sharing of the electrons (C-H, C-C, O=O)

6.     Describe a hydrogen bond and be able to identify where hydrogen bonds would form in a group of water molecules.

Hydrogen bond- weak association of attraction between a partial positive atom(hydrogen) and a partial negative atom

Hydrogen bonds would form between the oxygen on one water molecule and a hydrogen of a different water molecule. This is because the oxygen in a water molecule is partially negative, and the hydrogen of a water molecule is partially positive.

7.     Distinguish between intermolecular and intramolecular bonds.

Intermolecular- forces of attraction that exist between separate molecules

Intramolecular- forces that hold atoms together within a single molecule (much stronger)

8.     Describe how hydrogen bonds within water molecules give water the following properties:  Adhesion, Cohesion, high specific heat, high heat of vaporization, density of solid water, and solubility of many compounds.

Adhesion- binding of unlike molecules; capillary action of water transport in plants

Cohesion- binding of like molecules; water tension

High specific heat- how much energy is needed to heat up water

-        The more polar, the higher specific heat

High heat of vaporization- energy needed to change substance from liquid to gas

-        Cools surrounding surface, sweating cools the body

Density of solid water- ice is less dense that liquid water

-        Water reaches its max density at 4 degrees Celsius

-        Stratification (separation of layers) of lakes

Solubility- solvent= substance that dissolves another (water is the universal solvent); solute=substance that gets dissolved

-        Polar and ionic compounds dissolve easily in water

-        LIKE DISSOLVES LIKE

9.     Differentiate between a hydrophobic and hydrophilic compound.

Hydrophobic- “water fearing”

-        Nonpolar molecules (fats & oils)

-        Clump together to get away from the water

Hydrophilic- “water-loving”

-        Polar molecules

-        H-bonds form between substance & water

10.  Describe the concentration of hydrogen ions as a value on the pH scale.  Compare two solutions in amount of hydrogen ions and/or pH value.

On the PH scale there is a difference of 10 H+ between each level, and then you multiple them together to find how the difference on H+ between each level.

pH= -log10[H+]

Ex) water= pH 7

      New pH= 9

      100 times less H+

      Basic

11.  Distinguish between acids and bases.

Acids- pH<7; donates H+ & increases the concentration of H+ in a solution

Bases- pH>7; donates OH- or otherwise binds excess H+ & decrease the H+ concentration in a solution

12.  Describe a buffer system.

Helps to resist the change in pH; contains a pair of substances (one acid, one base)

13.  Describe major components to the water cycle:  Evaporation, transpiration, precipitation, etc.

1)     Liquid water from Earth’s surface evaporates (water to water vapor) into atmosphere; this occurs directly from the surfaces of oceans, lakes, and rivers

2)     Transpiration- water loss through plant leaves stomata’s

3)     Water vapor condenses into clouds as liquid or frozen droplets and is eventually followed by precipitation (rain or snow), returning water to the Earth’s surface

4)     Percolation- water infiltrates the ground and is stored in ground water

14.  Describe major components to the nitrogen cycle:  Atmospheric nitrogen, ammonia, Nitrates, Ammonium, Nitrites, denitrification, ammonification, nitrogen fixation, etc.

Atmospheric nitrogen- Nitrogen gas (N2) that makes up the majority of the Earth’s atmosphere (78%); most plants & animals cannot use N2

1)     Nitrogen fixation- synthesis of nitrogen containing compounds from N2

2)     Ammonia is created and dissolves in water

3)     Ammonification- converts nitrogenous waste from living animals or from the remains of dead animals into ammonium (NH4+) by certain bacteria & fungi

4)     Nitrification- ammonium is converted to nitrites (NO2-), and nitrites are converted to nitrates (NO3-)

5)     Denitrification- converts nitrates into nitrogen gas, allowing it to reenter the atmosphere

6)     Dead zone- area depleted of their normal flora & fauna due to excess phosphorus and nitrogen that enters these ecosystems from fertilizer runoff

15.  Describe major components to the carbon cycle:  respiration, photosynthesis, etc,

Carbon fixation- metabolic reactions that make nongaseous compounds from gaseous on

Photosynthesis- plants use sunlight, water, and carbon dioxide to create carbon and the bonds store energy for later in the use of respiration

Aerobic cellular respiration- break down high-energy carbon compounds to obtain cellular energy (ATP); requires oxygen obtained from atmosphere, and release carbon dioxide

16.  Recognize the following functional groups and be able to identify polar/nonpolar/acid/base properties:  Hydroxyl, carbonyl, carboxyl, amino, sulfhydryl, phosphate, methyl

Hydroxyl- polar

Carbonyl- polar

Carboxyl- polar, acidic (releases H+)

Amino- polar, basic (accepts H+)

Sulfhydryl- polar

Phosphate- polar, acidic

Methyl- nonpolar

17.  Understand how monomers can be linked together to form a polymer via dehydration synthesis (condensation) reactions, how a polymer can be broken apart via hydrolysis reactions.

Dehydration synthesis- building a polymer from monomer subunits; done by removing a water molecule (-OH) + (H+)

Hydrolysis- breaking polymer into a monomer; done by inserting a water molecule

-        Releases energy too

18.  Differentiate between the 4 classes of biological (organic) compounds.

Carbohydrates: monosaccharides are monomer subunit

-        All have a C:H:O ratio of approx. 1:2:1

-        Polar (hydrophilic), dissolve in water, used for storage of energy

Lipids: does not have a monomer subunit (if there was one it would be fatty acids)

Proteins: amino acids are monomer subunits

Nucleic Acids: monomer subunit are nucleotides

-        Each nucleotide consists of a 5-carbon sugar, phosphate, and nitrogenous base

19.  Given the molecular structure of a compound, identify the compound as either a monosaccharide, disaccharide, polysaccharide, nucleotide, amino acid, dipeptide, saturated fatty acid, or unsaturated fatty acid.

Monosaccharide- will have a C:H:O ratio of 1:2:1 (glucose, fructose, galactose)

Disaccharide- two monosaccharides (maltose, lactose, sucrose)

Polysaccharide- many monosaccharides (starches, cellulose, chitin)

Nucleotide- consists of 5 carbon sugar, phosphate, nitrogenous base

Amino acid-

Dipeptide- bond between two amino acids

Saturate fatty acid- contains no carbon-carbon double bonds in the carbon backbone

-        Packed tightly & exist as solids at room temp. (butter, fat in meats)

Unsaturated fatty acid- contains at least one carbon-carbon double bond in the carbon backbone

-        Monounsaturated= one double bond

-        Polyunsaturated= more than one double bond

-        Most unsaturated fats are liquids at room temp. (oils)

20.  Given the structure of an amino acid, classify the amino acid as polar, non-polar, or charged.

Differ in “R” side groups between amino acids

Can be polar (-OH, -SH, H2N), nonpolar (methyl groups), or charged

21.  Differentiate between the primary, secondary, tertiary, and quaternary structure of a protein (polypeptide).

Primary- number and sequence of amino acids

-        Change in the nucleotide sequence of DNA could lead to a change in amino acid, which could lead to a change in protein structure & function

Secondary- local folding of the polypeptide(protein)

-        Alpha-helix: formed by a hydrogen bond between oxygen in carbonyl group & an amino acid 4 positions down the chain

-        Beta-pleated sheet: hydrogen bond between atoms on the backbone of the polypeptide chain

Tertiary- unique three-dimensional structure of a polypeptide

-        Due to chemical interactions between R-groups of an amino acid (intramolecular bonds)

o   Hydrophobic interactions, ionic bonding, hydrogen bonding, disulfide linkage

Quaternary- interactions between several (2+) polypeptides that make up a protein

-        Weak interactions between subunits help stabilize the structure

-        Intermolecular bonds

22.  Understand the general layout of a membrane structure including hydrophobic and hydrophilic (amphipathic) components.

Amphipathic molecule- have two sides: a polar head, and a nonpolar tail

Polar side face the outside, while the nonpolar tails congregate towards the middle

23.  Differentiate and describe the function of the major components to the membrane:  Phospholipids, Proteins (integral and peripheral), carbohydrates (glycolipids & glycoproteins), and cholesterol.

Phospholipids: amphipathic molecules, and form the plasma membrane

-        Main separating layer from inside and outside the cell

Proteins

-        Integral: span the length of the membrane; transport ions across membrane, cell communication, enzymes (allow reactions to occur faster)

-        Peripheral: on the edge of the membrane; cellular communication, works with cytoskeleton to move cell

Carbohydrates: glycolipids & glycoproteins help the cell bind required substances in the extracellular fluid

Cholesterol: is a lipid and hydrophobic (sticks within nonpolar membrane)

-        Makes the cell membrane more flexible when cold, and more rigid when warm

24.  Know the four components to a biological membrane, how they are arranged on a membrane & their function.  Be sure to apply the words hydrophobic and hydrophilic to the membrane.

25.  Contrast passive and active transport in which way they move substances (up or down concentration gradients) and if they use energy or not.

Passive transport: does not require energy, high to low concentration, might or might not require a protein

Active transport: requires energy, low to high concentration (against conc. gradient), requires a protein

26.  Describe the following transport mechanisms: simple diffusion, facilitated diffusion, osmosis, active transport including giving examples of substances that are transported via that mechanism

Simple diffusion: passive transport, stuff easily passes through membrane (small & nonpolar)

Ex) oxygen, carbon dioxide, steroids

Facilitated diffusion: passive transport, transport things that cannot easily go through membrane (ions, large items), need use of proteins (channel, carrier)

Osmosis- passive transport (facilitated diffusion), movement of water through a semipermeable membrane, protein is called an aquaporin and some of the membrane is “leaky”

Primary active transport- moves ions across a membrane and creates a difference in charge across that membrane, which directly dependent on ATP

EX) sodium/potassium pump

Secondary active transport- does not directly require ATP: instead, it is the movement fo material due to the electrochemical gradient established by primary active transport

EX) glucose coupled with sodium

27.  Identify a solution as hypertonic, isotonic, or hypotonic given solute concentrations inside a cell and of a solution.  Also, predict the net movement of water (cell gets bigger or smaller)

Hypotonic: lower solute concentration- H20 flows into the cell and cell gets bigger

Hypertonic: higher solute concentration- H20 flows out of cell and cell shrinks

Isotonic: same solute concentration- H20 flows out of cell and into cell evenly

28.  Understand the processes of endocytosis and exocytosis

Endocytosis- type of active transport that moves substances, including fluids and particles, into a cell; cell’s plasma membrane invaginates, forming a pocket around the target particle

-        Phagocytosis: “cell eating”; process by which a cell takes in large particles, such as other cells or relatively large particles

-        Pinocytosis: “cell drinking”; process that takes in molecules, including water, which the cells needs from the extracellular fluid, and results in a much smaller vesicle than does phagocytosis

-        Receptor mediate endocytosis: employs receptor proteins in the plasma membrane that have a specific binding affinity for certain substances

Exocytosis- process of passing bulk material out of a cell