BIO-111 EXAM 1 JCC

What is the definition of science, and how does it relate to inquiry?

Science is an approach of knowledge and understanding the natural world driven by inquiry, the search for information and explanation of natural phenomena

qualitative data?

non-numerical data which can be recorded using descriptions

quantitative data?

numerical data that can be organized into tables and graphs

Inductive reasoning?

A type of logic in which generalizations are based on a large number of specific observations. (specific->general) EX: every swan ive seen is white so all swans must be white

Deductive reasoning?

reasoning in which a conclusion is reached by stating a general principle and then applying that principle to a specific case (general->specific) EX: all mammals are warm blooded therefore a whale much be warm blooded

Requirements of a hypothesis

testable, falsifiable, and logical

Steps involved in conducting an experiment

1. Observations

2. Prediction

3. Hypothesis

4. Experiment

5. Conclusion

How do controlled experiments help scientists test hypothesis?

They carry out experiments in controlled conditions as to isolate the effect of a single factor and evaluate its impact

Independent variables?

Factors that are manipulated in an experiment or do not depend on anything, like time.

dependent variables?

a variable that changes in response to the independent variable

Scientific theory and its difference from a hypothesis

A well-tested explanation for a wide range of observations or experimental results. Different from a hypothesis because it explains a broad question and is supported by more data.

Why is good communication and teamwork essential in scientific research?

Science is a social activity, therefore information must effectively be shared to ensure repeatability which allows others to build off of or disprove ideas.

Model organisms?

A particular species chosen for research into broad biological principles because it is representative of a larger group (genetically simple) and usually easy to grow in a lab. EX: Fruit fly and Ecoli

How do science, technology, and science interact and influence each other?

Science is used to explain natural phenomena and technology applies this knowledge to benefit society.

Matter?

Anything that has mass and takes up space + makes up elements

Elements?

a substance that cannot be broken down into simpler substances by chemical reaction

Compounds?

2 or more atoms from different elements combined in a fixed ratio

Essential elements found in living organisms and the percentage they make up?

Carbon, Hydrogen, Oxygen, and Nitrogen make up 96% of life (CHON!!!)

Trace elements?

required by an organism in only minute quantities EX: Iodine and iron

Atom?

Smallest unit of matter composed of subatomic particles

Subatomic particles?

protons, neutrons, electrons

Protons

Positively charged particles in the atomic nucleus; in a balanced atom # protons = # electrons

Neutrons

particles with no charge, found in the atomic nucleus and make up the bulk of atomic mass.

Electrons

Negatively charged particles that form a cloud around the atomic nucleus. (In a balanced atom # electrons = # protons)

Atomic Number?

the number of protons in the nucleus of an atom. Element identity is SOLELY determined by this.

Atomic mass?

The total mass of an element and is calculated by # protons + # neutrons.

Isotopes

Atoms with the same number of protons but different numbers of neutrons

What happens to an isotope when it decays? (Radioactive isotopes)

Particles and energy are released

Uses of radioactive isotopes?

Cancer therapy and fossil dating

How does electron distribution affect an atom's chemical properties?

Elements are arranged in rows on the periodic table which correlate to the number of electron shells in their atoms and relates to the number of valance electrons which affects its ability to bond.

Octet rule?

States that atoms lose, gain or share electrons in order to acquire a full set of eight valence electrons. First energy shell holds up to 2 electrons and the second holds up to 8.

Covalent bonds

Bonds created by !SHARING! electrons with other atoms.

Ionic bonds

Formed when one or more electrons are !TRANSFERED! from one atom to another

Electronegativity

a measure of the tendency of an atom to attract a bonding pair of electrons and determines whether the bond between 2 atoms is polar or non polar

Polar covalent bond

A covalent bond in which electrons are not shared equally between 2 atoms of !DIFFERENT! electronegativity (EX: H-O)

Nonpolar covalent bonds

A type of covalent bond in which electrons are shared equally between two atoms of !SIMILAR! electronegativity. (EX: H2)

Hydrogen bond

A type of weak chemical bond formed when the slightly positive hydrogen atom of a POLAR COVALENT bond in one molecule is attracted to another molecule with a partial negative charge

Van der Waals interactions

weak attractions between POLAR OR NONPOLAR molecules, specifically between the charge fluctuations (transiently positive and negative regions) between molecules. ELECTRONS ARE NOT ALWAYS EVENLY DISTRIBUTED CAUSES TEMPORARY CHARGE FLUCTUATIONS.

Reactants

A starting material in a chemical reaction

Products

The elements or compounds produced by a chemical reaction.

Chemical equilibrium

a state of balance in which the rate of a forward reaction equals the rate of the reverse reaction and the concentrations of products and reactants remain unchanged

Meaning of a double arrow on a chemical reaction

All reactions are reversable

Why is water considered a polar molecule

The oxygen end is slightly negative and the hydrogen end is slightly positive

How do covalent bonds contribute to the properties of water?

(Water's POLAR covalent bonds create positive and negative poles which pave the way for hydrogen bonds; Hydrogen bonds cause the properties of water)

Enables cohesive and adhesive behavior through bonding between opposite charges, versatility as a solvent through the polarity of water's ability to dissolve many ionic and polar substances, ability to moderate temperature as its polarity creates strong hydrogen bonds which require extra energy to break, and expansion by freezing through the open structure of its strong hydrogen bonds.

Cohesion

Attraction between molecules of the same substance and contributes to water's surface tension by creating a barrier between water and air molecules.

Adhesion

An attraction between molecules of different substances. Affects water's behavior in plants by allowing it to go against gravity through adhesion to plant cell walls

How does water's high specific heat contribute to temperature regulation?

Water's high specific heat allows it to absorb lots of heat without changing temperature. Specifically, its hydrogen bonds absorb heat when broken and release heat when formed.

Significance of water's high heat of vaporization

the quantity of heat a liquid must absorb for 1 g of it to be converted from the liquid to the gaseous state; significant because explains why steam can burn humans severely and vaporization paves the way for evaporative cooling

Evaporative cooling

The process in which the surface of an object becomes cooler during evaporation, caused by molecules with the highest heat/ kinetic energy evaporating and leaving behind the cool water. It is significant because it prevents leaves from getting too warm and the human body too hot.

What happens to water when it freezes, and why is this important for life on Earth?

When frozen, molecules begin to slow down. The unique structure of hydrogen bonds keeps molecules at "arms length", causing a decrease in density. This is important because it creates a barrier between the cold air and sorta warm ocean water. If ice didn't float, large bodies of water would freeze completely.

hydrophobic

Water fearing

hydrophillic

water loving

Acids

increase the concentration of Hydrogen ions (H+) and decreases hydroxide ion (OH-) concentration

base

decrease the concentration of Hydrogen ions (H+) and increases hydroxide ion (OH-) concentration

buffers

weak acids or bases that can react with strong acids or bases to prevent sharp, sudden changes in pH. this process happens in blood.

Carbon

Called the backbone of line because everything organic has carbon, it can form 4 bonds. without it the diversity on earth would NOT be possible. Often forms a "backbone" shaped structure with other molecules use.

What makes organic chemistry different from other branches of chemistry?

Organic chemistry is the study of any compounds that have carbon, making them organic compounds

How do small organic compounds form larger molecules in living organisms?

through carbon's ability to form 4 bonds, making it easier for small organic compounds to form complex compounds

macronutrients

A chemical substance that an organism must obtain in relatively large amounts. provide energy, support body functions, and promote a healthy body

micronutrients

Vitamins and minerals needed in small amounts. Essential for growth, brain development, immune functions, and disease prevention.

How does carbon's ability to form four bonds contribute to the diversity of organic molecules?

with the ability to form four bonds, carbon can create complex carbon skeletons that can vary in length, branches, and bonds. These complex skeletons lead to diversity

How do carbon chains vary in length and structure, and how does this impact their function?

Carbon chains can become shorter and longer, can possess several branches, can form 4 bonds, can form one/double/triple bonds, and can form rings. These properties impact the distribution of electrons, allowing chemical groups to influence the carbon.

hydrocarbons

Compounds composed of only carbon and hydrogen. hydrophobic and non polar, can release a large amount of energy through reactions.

structural isomers

differ in the covalent arrangements of their atoms

cis-trans isomers

have the same covalent bonds but differ in spatial arrangements

enantiomers

isomers that are mirror images of each other

isomer

Compounds with the same formula but different structures.

ATP

(adenosine triphosphate) main energy source that cells use for most of their work. Stores potential energy in water, provides energy for cells.