AP Biology 22/23 Chapter 2 - Chemical Context of Life

Matter

has mass and takes up space

How does gravity impact matter?

Gravity has an affect on matter

What does matter consist of

Elements and Compounds

How does energy impact matter?

Energy moves matter

potential energy

Stored energy

kinetic energy

energy that possesses motion

Element

A "pure" substance

Can an element be broken?

No; Can’t be broken down by “ordinary” means to another substance

Is Hydrogen (H) an element or compound?

Element

Is Nitrogen (N) an element or compound?

Element

Compound

Two or more different elements combined in a fixed ratio

Is water (H2O) an element or compound?

Compound

Is carbon dioxide (CO2) an element or compound?

Compound

Life is 96% of what elements?

Carbon (C), Hydrogen (H), Nitrogen (N), and Oxygen (O)

Life is 4% of what elements?

Calcium (Ca), Potassium (K), Phosphorus (P), and Sulfur (S)

What element is found in DNA?

Phosphorus (P)

trace element

an element that occurs at very small quantities in the body but is nonetheless important for many biological processes

What are trace elements found in life?

Iron (Fe) and Iodine (I)

Atom

smallest unit of matter that retains properties of an element

Mass (dalton or AMU) of neutron

1

Mass (dalton or AMU) of proton

1

Mass (dalton or AMU) of electron

negligible

Location of neutron

nucleus

Location of proton

nucleus

Location of electron

shell

Charge of a neutron

0

Charge of a proton

+1

Charge of a electron

-1

4

Mass number (protons + neutrons)

4
He

Symbol

4
He
2

atomic number (protons or electrons)

2

atomic number

2
2

valence electrons

2
2
He

Symbol

2
2
He

4

Mass number

In isotopes what varies?

Neutrons

In isotopes what stays the same?

Protons

Radioactive isotopes are used as what?

They are used as tracers for medical diagnoses

Covalent polar bond

covalent bond between atoms that differ in electronegativity

covalent bond

a chemical bond that involves sharing a pair of electrons between atoms in a molecule

electronegativity

the tendency of an atom or a functional group to attract electrons toward itself. How attractive to electron is a particular atom

Covalent nonpolar bond

e- shared equally; eg. O2 or H2

1st strongest bond types

Covalent

Ionic bond

One atom is completely negative and one is completely positive. 2 ions (+/-) bond (givers/takers) (Na+Cl-)

2nd strongest bond

Ionic bonds

Hydrogen bond

H of polar covalent molecule bonds to electronegative atom of other polar covalent molecules

2nd Weakest bond

hydrogen bonds

1st weakest bond

Van der Waals Interactions

Van der Waals Interactions

slight, fleeting attractions between atoms and molecules close together (Eg. gecko toe hairs + wall surface). Brief moment of attraction in large compounds. very weak, easy to disrupt.

What bonds are important to life?

All bonds are important to life

Chemical equilibrium

point at which forward and reverse reactions offset one another exactly

What is surface tension a result of?

increased hydrogen bonds forcing between water molecules at the surface

What do living systems require?

a constant input of energy

What do Carbohydrates contain?

Carbon

What do Proteins contain?

carbon & nitrogen

What do nucleic acids contain?

carbon, nitrogen, & phosphorus

What do lipids contain?

Carbon & Phosphorus

What is necessary from the environment to build new molecules?

Atoms and molecules

What is used to build all macromolecules to store energy and form cells?

Carbon

What is used to build proteins and nucleic acids?

Nitrogen

What is used to build nucleic acids and certain lipids?

Phosphorus

Monomers

Chemical subunits to create polymers.

Polymer

Macromolecules made of many monomers

Covalent bond

A bond formed between two interacting molecules

Do polymers have to relate to a specific monomer?

Yes. polymers are specific to monomers they consist of.

What monomer does the polymer carbohydrate relate to?

The monomer Monosaccharide

What monomer does the polymer protein relate to?

The monomer amino acid

What monomer does the polymer nucleic acid relate to?

The monomer nucleotide

What monomer does the polymer lipids relate to?

Lipids don't have true monomers. The closest is fatty acids.

What are the subcomponents of a water molecule?

H and OH

Dehydration Synthesis

Subcomponents of a water molecule are removed from interacting monomers and a covalent bond forms between them.

What will always be a byproduct of dehydration synthesis?

A polymer and water

Hydrolysis reactions

When water molecules are hydrolyzed into subcomponents and each subcomponent is added to a different monomer

What are dehydration synthesis reactions used to create?

Macromolecules

What happens to polymers in a hydrolysis reaction?

Polymers are hydrolyzed into monomers.

What happens to monomers during dehydration synthesis?

Monomers will lose an entire hydroxide while the other monomer will lose one hydrogen from it's hydroxide

What kind of bond forms in place of the hydroxide and hydrogen removed from a dehydration synthesis?

A covalent bond

What else are protein monomers called?

Amino acid

Amino group terminus for amino acids

NH2

Carboxyl group terminus

COOH

During dehydration synthesis what happens to the carboxyl group?

A hydroxide is lost of one amino acid.

During dehydration synthesis what happens to the hydrogen atom?

A hydrogen atom is lost from the amino group of another amino acid.

Can proteins undergo a hydrolysis reaction?

yes

Can covalent bonds in amino acids be broken?

yes

What is hydrolysis reaction used to do?

Hydrolysis reactions use water to break down biological macromolecules

What part of the table has the most electronegativity?

Top right

Polar covalent

Uneven distribution of charge. More negative or more positive (H2O)

Nonpolar covalent

Everything is equally shared. Completely negative or completely positive

What are ionic bonds affected by?

The enviornment (water)

Are proteins able to break down?

Yes

What do acids have excess of?

Hydrogen

What do Hydrogen bonds occur between?

They occur between adjacent molecules that have hydrogen atoms inside them.

What maintains homeostasis?

Chemical equilibrium