Chapter 2 - The Chemistry of Life

Hydrogen bonds

Hydrogen bonds

________ make water molecules spread out as the water freezes into ice.

Dehydration synthesis

________ binds two amino acids together, forming a dipeptide.

chain of amino acids

A(n) ________ folds up into a unique 3- D shape to become a protein.

Buffer solutions

________- maintain a constant pH by absorbing or releasing H+ into a solution.

Hydrolysis

________- chemical reactions that break polymers apart.

Chemical bonds

________ are determined by electrons.

Cholesterol

________ regulates the fluidity of animal cell membranes; it is also used to synthesize many sex hormones.

Triglycerides

________ (fats and oils)- energy rich, needed for long term energy storage.

Atom

________- smallest piece of an element that retains the characteristics of the element.

Cohesion

________- tendency of water molecules to stick to one another.

Enzymes

________ form bonds between two monomers.

Noble gases

________- full and do not bond.

ionic bonds

In ________, both atoms get full outer shells, so both atoms become stable.

Electrons

________ spend less time- slightly positive charge (atom)

Proteins

________ have many different structures and functions.

Monosaccharides

________ are simple sugars; they are the monomers that make up larger carbohydrates.

Polysaccharides

________ are long chains of carbohydrates.

Adhesion

________- allows water molecules to form hydrogen bonds with other molecules.

number of neutrons

The ________ may vary which causes each isotope to have different masses.

Saturation

________ gives triglycerides different properties.

single unit

Monomers- ________ of carbohydrate, protein, or nucleic acid.

Steroids

________- third class of lipids.

atomic weight

The ________ on the periodic table is the average mass.

similar electronegativity

When atoms have ________, neither will pull electrons more strongly than the other.

Organic molecules

________ such as carbohydrates, proteins, and fats are common in our diets.

Acidic solutions

________ have a low pH and a high H+ concentration.

Protons

________ and neutrons- in atomic nucleus.

Monomers of proteins

________ are amino acids.

Energy shells

________, orbitals, contain the atoms electrons.

Primary structure

________ (sequence): Amino acid sequence of a polypeptide.

Element

________- a substance that can not be broken down by chemical means into other substances.

negative atom

Partially ________ attracts a hydrogen atom with partially positive charged.

positive charge

Slightly ________ on the hydrogen atom attracts the negatively charge of a neighboring water molecule.

PH scale

________ shows the amount of H+ ions in solutions.

Dehydration synthesis

________ binds two simple sugars together, forming a disaccharide.

Hydrolysis

________ separates fatty acids from glycerol.

Cohesion

________ and Adhesion allows water to "climb "from a trees roots to its highest leaves.

Proteins

________ are the "workers "of the cell; they do almost everything.

Electrons

________ can completely transfer over to highly electronegative atoms.

Atoms

________ do not have charge.

Hydrogen bonds

________ make water resist changes in temperature.

Dehydration synthesis

________- chemical reaction that joins monomers.

Hydrolysis

________ breaks disaccharides into monosaccharides.

Electrons

________- surround the atomic nucleus.

Atoms

________ are more stable when their outer shells have no vacancies.

Hydrogen bonds

________ form between adjacent molecules or between different parts of a large molecule.

Dehydration synthesis

________ binds two nucleotides which creates DNA and RNA.

Hydrolysis

________ separates dipeptides and polypeptides into individual amino acids.

Electrons

________ are arranged in pairs on the shells.

Atoms

________ are organized into molecules.

Element

a substance that cannot be broken down by chemical means into other substances

mass

things inside

weight

gravitational pull

Atom

smallest piece of an element that retains the characteristics of the element

electrons

surround the atomic nucleus

protons and neutrons

in atomic nucleus

protons

positively charged (+), mass 1

neutrons

neutral (0) mass 1

electrons

negatively charged (-), mass 0

Atomic number

number of protons

Atom mass number

number of protons and neutrons

Ion

charged atom

Covalent Bonds

when atoms share electrons

Double bonds

share 4 electrons between atoms

Noble gases

full and do not bond

Electrons spend more time

slightly negative charge (atom)

Electrons spend less time

slightly positive charge (atom)

Different electronegativity

polar covalent bonds

atom that loses an electron

positively charged

atom that gains

negatively charged

H

H bond in hydrogen bond

electronegativity difference is moderate or large (0.4

1.7)

O

H bond in water molecule

Two elements with similar/moderately different electronegativities will

form nonpolar covalent bonds

Two elements with very different electronegativities will

form ionic bonds

Cohesion

tendency of water molecules to stick to one another

Adhesion

allows water molecules to form hydrogen bonds with other molecules

Water dissolves hydrophilic (water

loving) substances

Water does not dissolve hydrophobic (water

fearing) solutes

Example

Lipids (butter) that have nonpolar covalent bonds

Acidic pH <7

the lower the pH, the stronger the acid

Alkaline (basic) pH > 7

the higher the pH, the stronger the base

Have more OH

ions than H+ ions

Buffer solutions

maintain a constant pH by absorbing or releasing H+ into a solution

pH too high

releases H+ to lower pH

pH too low

absorbs H+ to raise pH

Contain both carbon and hydrogen (ex

methane)

monomers

single unit of carbohydrate, protein, or nucleic acid

Dehydration synthesis

chemical reaction that joins monomers

Hydrolysis

chemical reactions that break polymers apart

example

ribose, glucose, and fructose

ex

sucrose

cellulose

structure

starch

energy

glycogen

energy

Collagen

Create cellular structures

Actin and Myosin

Produce muscle contractions

The 20 different amino acids have 20 different R

groups

A chain of amino acids folds up into a unique 3

D shape to become a protein

Primary structure (sequence)

Amino acid sequence of a polypeptide