AP Biology- Campbell (Chapter 2)

AP Biology is an advanced placement biology course that covers a wide range of biological topics at a college level. It delves deep into concepts such as cellular processes, genetics, evolution, ecology, and more. The course is designed to be challenging and rigorous, and successful completion often results in college credit. Students who take AP Biology gain a comprehensive understanding of the principles of biology and develop critical thinking and analytical skills

What is matter?

Anything that takes up space and has mass

What is an element?

Any substance that cannot be broken down into any other substance by chemical reactions

What is a compound?

a substance consisting of two or more different elements combined in a fixed ratio

What four elements make up 96% of living matter?

carbon, hydrogen, oxygen, nitrogen

What is an essential element?

A chemical element required for an organism to survive, grow, and reproduce.

What is a trace element?

An element required by an organism in only minute quantities, some are needed by all forms of life (example: iron), others are required by certain species.

What is the atomic number and mass of helium?

2, 4.002602

What is a neutron?

A subatomic particle having no electrical charge (electrically neutral), with a mass of about 1.7x10^-24g, it's found in the nucleus of an atom.

What is a proton?

A subatomic particle with a single positive charge, with a mass of about 1.67262192 × 10^-27kg, it's found in the nucleus of an atom.

What is an electron?

A subatomic particle with a single negative charge and a mass with about 1/2,000 that of a neutron or proton. One or more electrons move around the "cloud" of an atom. (outside the nucleus)

When did Lauren Graduate?

In 2005, she graduated from Biola University with a B.S. in Biological Sciences

Whats an atomic number?

the number of protons in the nucleus of an atom, unique for each element and designated by a substript.

What is an isotope?

one of several forms of a single element, which contains the same number of protons but different numbers of neutrons, thus differing in atomic mass.

What is atomic mass?

Total mass of an atom (for an element with more than one isotope, the atomic mass is the mass of the average masses)

What are electron shells?

Energy level of electrons at a characteristic average distance from the nucleus of an atom. (the outside part of an atom around the atomic nucleus)

What is energy?

the capacity to cause change, especially to do work (to move matter against an opposing force)

What is a radioactive isotope?

An unstable form of a chemical element that releases radiation as it breaks down and becomes more stable

How is a radioactive isotope used in medicine?

They are often used to detect (diagnosis) and treat (therapy) cardiovascular diseases and cancer

What is potential energy?

It's the energy that matter posses because of it's location or structure.

What determines potential energy?

position of shared electrons and distance from positive charges in nuclei; atomic nucleus and electron energy level.

Why does an electron in the last energy shell have more potential energy than one in the first energy shell?

Because it's farther away from the nucleus.

A lithium atom has 3 protons and 4 neutrons; What is its mass number?

7

What is the only subatomic particle that is directly involved in the chemical reactions between atoms?

Electrons, this is because they are on the outer-most shell and have low ionization energy. (they are valence electrons)

What is a valence eletron?

They are electrons in the outermost shell of an atom, and that can participate in the formation of a chemical bond if the outermost shell is not closed

What determines the chemical behavior of an atom?

It's determined by the number and the configuration of the electrons in the atom. Also the number of valence electrons.

How many electrons can the first two electron shells hold? (in total)

10

What is an orbital?

A three-dimensional region around the nucleus that indicates the probable location of an electron

what's an anion?

A negatively charged ion

what's a cation?

A positively charged ion

What's electronegativity?

The measure of the tendency in which atoms attract a bonding pair of electrons to itself

What's a covalent bond?

Sharing of a pair of valence electrons by two atoms

What's a compound bond?

A bond between two or more DIFFERENT elements.

What is a nonpolar covalent bond?

A type of covalent bond in which electrons are shared equally between two atoms of similar electronegativity.

What is a polar covalent bond?

A covalent bond in which electrons are not shared equally; the electronegativity are not similar.

Why is oxygen more electronegative than hydrogen?

Because oxygen has more valence electrons, shared electrons are more pulled towards oxygen.

What is an ionic bond?

A chemical bond that's formed when an atom transfers and electron to another Atom

What is a 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 the slightly negative atom of a polar covalent bond in another molecule.

van der Waals interactions

Weak attractions between molecules or parts of molecules that result from transient local partial charges.

Types of Bonds and Interactions: Strong-Weak

Ionic bond > Covalent bond > Hydrogen bond > Van der Waals interaction.

What does molecular shape determine?

How biological molecules specifically recognize and respond to one another

What is dynamic equilibrium?

when the forward and reverse processes occur at the same rate, resulting in no observable change in the system.

Use morphine and endorphins as examples to explain why molecular shape is crucial in biology.

The precise shape of a molecule is usually very important to its function in the living cell, and crucial in biology because it determines how biological molecules recognize and respond to one another with specificity. Morphine and other opiates have similar shape to endorphins, and can therefore mimic the pain-relieving effect of endorphins by binding to endorphin receptors in the brain.

What is meant by dynamic equilibrium? Does this imply equal concentrations of each reactant and product?

Means that reactions are still going on, but with no net effect on the concentrations of the reactants and products. Equilibrium does not mean that the reactants and products are equal in concentration, but only that their concentrations have stabilized at a particular ratio.