Chapter 2 Bio

Life is composed of…

matter

Matter is anything that

occupies space and has mass

Common Elements of Living Organisms

C,O,H,N (carbon, oxygen, hydrogen, nitrogen)

Atom

the smallest unit of matter that retains all chemical properties of an element

The nucleus contains…

protons and neutrons

The more neutrons and protons in the center of the atom…

the closer electrons are to the nucleus, which means they can be given away easier

Subatomic particles are _____, _______, and ________

protons, neutrons, and electrons

The mass of an electron is…

1/1800 amu

Atomic number

number of protons

Atomic mass =

Protons + neutrons

Isotopes

same number of protons, but neutrons vary

Radioisotopes

unstable isotopes that emit neutrons, protons, and electrons

Atoms with a neutral charge have the same number of…

protons and electrons

Electrons exist on the shells…

closest to the nucleus

Octet rule

when the first two outer shells are filled, each have 8 electrons

The closer the electrons are to the nucleus…

the stronger the pull is

The lower the atomic number…

the lower the pull; more likely to form bonds with other atoms

Electron orbitals helps us to…

predict where an electron might be at any given time

The stronger the pull…

the more organized the movements of electrons

Chemical reactions are

changes in distribution of electrons between atoms

1 mol of a substance is the amount whose mass in _____ equals its molecular mass in _______.

grams; amu

In covalent bonds, electrons are ________

shared

In ionic bonds, atoms _____ or _____ electrons

lose; gain

Metals ______ electrons to achieve the octet rule

lose

Nonmetals _______ electrons to achieve the octet rule

gain

Gaining an electron gives a more _____ charge

negative

Losing an electron gives a more ______ charge

positive

What consist of anions and cations held together by ionic bonds?

salts

Salt is a _______,__ but NOT a _________

compound; molecule

Covalent bonds in which there is unequal sharing of the electrons are called _______.

polar bonds

Covalent bonds in which there is equal sharing of the electrons are called _______.

non-polar bonds

Both bond type and molecular shape determine if a molecule is ____ or _____.

polar; nonpolar

Weak attractions between two or more molecules in close proximity due to changes in electron density are called _______.

Vand der Waals interactions

Weaker bonds between a proton in one atom, and an electronegative atom in the other are called _________.

hydrogen bonds

Water makes up ______ of the human body

60% - 70%

The most critical molecule for life on earth is…

water

In water, oxygen has the slightly _____ charge

negative

In water, hydrogen has the slightly ______ charge

positive

In liquid water hydrogen bonds are constantly _____, _____, and _______.

made, broken, and remade

In _______, water is heated, kinetic energy increases, causing hydrogen bonds to break + water molecules escape as gas

gas

In _______ temperature is lowered and crystalline structure is maintained.

solid water

Hydrogen bonding makes ice _______ dense than liquid water, which is why it floats in water

less

______ and ______ molecules can dissolve in water

Ions; Polar

Water is a ________

universal solvent

Compounds dissolved or mixed in with the water are called _____.

solutes

Water molecules at the liquid-gas interface stick together due to hydrogen bonding (an attraction between water molecules and other water molecules) is called ______.

cohesion

Surface tension is caused by _______.

cohesion

An attraction between water molecules and other molecules is called ________.

adhesion

Capillary actions is caused by ________.

adhesion

Solutions with high H+ concentration are ______.

acidic

Solutions with high OH- concentration are _______.

alkaline (basic)

Acidic solutions are more likely to _____ protons

donate

Alkaline solutions are more likely to ______ protons

accept

Normal human pH is _______

7.4

Carbon is a key component of ________.

macromolecules (proteins, carbohydrate, lipids and nucleic acids)

Each carbon has ____ electrons in the outer shell and forms _____ covalent bonds to fill the outer shell

\
This allows it to achieve the octet rule

four; four

Carbon is the _______ for macromolecules

backbone

Hydrocarbons are

hydrogen and carbon

Covalent bonds in hydrocarbons store _______

energy

When hydrocarbons are burned, energy is ________.

released

When carbon forms single bonds with other atoms, it’s shape is…

tetrahedral

When two carbon atoms form a double bond, it’s shape is…

planar, or flat

Single bonds ______ able to rotate

are

Double bonds _______ able to rotate, they are locked in place

are NOT

An important hydrocarbon ring used in some amino acids, cholesterol and its derivatives is called ________.

benzene

________ have different covalent arrangement of atoms

Structural isomers

________ have a different arrangement of atoms around a double bond

Geometric isomers

________ are mirror images

Enantiomers

Trans configuration carbons are on the _____ sides of double bond

opposite

Cis configuration carbons are on the _____ side of double bond

same

Fatty acids with double bond are _______

unsaturated

Fatty acids with no double bonds are _______

saturated

Functional groups interact with each other via ____ ______

hydrogen bonds

Name the functional group

Hydroxyl; Polar

Name the functional group

Methyl; nonpolar

Name the functional group

Carbonyl; Polar

Name the functional group

Carboxyl; Ionizes to release H+ into solution, which is why they are acidic

Name the functional group

Amino; Accepts H+ to form NH₃+, which is why they are basic

Name the functional group

Phosphate; Ionizes to release H+ into solution, considered acidic

Sulfhydryl

Polar

The type of bond in DNA is _________

hydrogen