Chapter 2: Chemistry Comes Alive

Define molecule and distinguish between a compound and a mixture.

A molecule is two or more atoms held together by chemical bonds. When the two or more atoms are different, this is called a molecule of a compound(H20). Mixtures are when two or more components are physically intermixed.

Explain the roles of ATP in cell metabolism.

ATP is a source of energy that cells can immediately use. It is the primary energy-transferring molecule in cells.

Define acid and base.

Acids release H ions(H+) or protons into a solution. Bases accept them.

Synthesis reaction

Atoms or molecules combine to form larger complexes. A+B->C

Covalent bonding

Atoms share an electron

Ionic bonding

Atoms transfer electrons from one atom to another. This causes one atom to be negative and another to be positive. Because they have opposite charges, the atoms will bond together.

Explain the role of electrons in chemical bonding and in relation to the octet rule

Atoms want to have a full valence shell with eight electrons so they will be stable. To do this atoms will share or exchange electrons.

Compare and contrast DNA and RNA.

Both are nucleic acids and house information crucial to the cell. However, they are very different. DNA is a doubles stranded helix with deoxyribose for its sugar. It has the base thymine. RNA is single stranded and has uracil in place of thymine. Its sugar is ribose.

Define chemical element and list the four elements that form the bulk of body matter

Cannot be broken down into simpler substances by ordinary chemical methods. Elements act as the building blocks of chemistry. Carbon, oxygen, hydrogen, and nitrogen make up 96% of our body weight.

Describe the major energy forms

Chemical energy:energy is stored in the bonds of chemical substances like ATP Electrical energy: results from the movement of charged particles like in the nervous system Mechanical energy: directly involved in moving matter like your legs pedaling on a bike Radiant/Electromagnetic energy: travels in waves like light and radio waves

Polar compounds

Created by the unequal sharing of electrons. The result is a molecule with a positive end and a negative end.

Define atom, list the subatomic particle, and describe their relative masses, charges, and positions in the atom.

Each element contains atoms which are more or less identical particles or building blocks. Each atom is made up of protons and neutrons which are housed in the nucleus and electrons which surround the nucleus. Protons have a +1 charge and weigh 1amu. Electrons have a -1 charge and weigh 0amu. Neutrons have a 0 charge and wiegh 1 amu.

Compare and contrast the fibrous and globular proteins.

Fibrous proteins are extended and strandlike and are often used in tissues. They are insoluble in water and very stable, providing mechanical support and tensile strength(collagen). Globular proteins are compact, spherical proteins. They are water soluble and chemically active. They are important to biological processes.

Hydrogen bonds

Hydrogen bonds are not true bonds like ionic and covalent. Hydrogen bonding is when a molecule with H is attracted to a negative part of another molecule.

Explain the role of dehydration synthesis and hydrolysis in the formation and breakdown of organic molecules.

In dehydration synthesis, one monomer donates a H while another donates an OH in order to join together. In other words, two join two pieces, the two pieces kick off a water molecule because an OH+H->H2O. In hydrolysis, the opposite takes place. In order to break apart the monomers, a water molecules is shoved back into them. One monomer takes the H, the other takes the OH.

Lipids

Includes fats, oils, phospholipids, and steroids. Lipids are made up of H, O, carbon chains, and sometimes Phosphorus. They are used for hormones, membranes, and more.

Exchange reaction

Involves synthesis and decomposition. AB+C->AC+B

Explain the importance of water and explain the properties of water.

It makes of 60-80% of the volume of most living cells. It has a high heat capacity(the temperature doesn't drastically change), high heat of vaporization(cools the body), and polar solvent properties(ionic compounds break apart in it like salt).

Carbohydrates

Made up of monomers or monosaccharides which can join together to form di- or polysaccharides. Carbs include sugars and starches. They are used for energy or fuel for the cell.

Differentiate between matter and energy

Matter is anything that occupies space and has mass. Energy is the capacity to do work, or to put matter into motion.

Differentiate between potential energy and kinetic energy

Potential energy is the capability to do work or move(like a ball sitting at a top of a ramp) and kinetic energy is doing work through movement(like a ball rolling down the ramp).

Describe the four levels of protein structure.

Primary: the sequence of amino acids forms the polypeptide chain Secondary:the primary chain forms spirals(alpha helix) and sheets(beta sheets) Tertiary: Superimposed on the secondary structure. Alpha helices and/or beta sheets are folded up to form a compact globular molecule held together by intramolecular bonds. Quaternary structure: Two or more polypeptide chains, with its own tertiary structure, combine to form a functional protein.

Explain the importance of salts to body homeostasis.

Salts control things like nerve impulses and muscle contractions. The kidneys are important to keeping this ionic balance. When one thing is not in balance, it causes others to be imbalanced as well, resulting in the stopping of crucial biological processes.

Suspension

Solute paricles are very large, settle our and may scatter light(blood)

Colloids

Solute particles are larger than in a solution and scatter light, do not settle out.(gelatin)

Solutions

Solute particles are very tiny, do not settle out or scatter light(mineral water)

Describe factors that affect chemical reaction rates.

Temperature: increase kinetic energy and force of collisions Concentration: more reacting molecules are present Particle Size: smaller particles react faster because they move faster Catalysts: increase the rate without being involved

Atomic weight

The average of all the isotopes of a certain element taking into account the abundance of each isotope.

Nonpolar compounds

The molecule is electronically equal.

Atomic mass

The sum of the masses of the protons and neutrons. Some elements have isotopes. Isotopes have the same number of protons but different number of neutrons. For example, there is Carbon 12 and Carbon 14. Both has 6 protons, but they have different weights because of a difference in the number of protons.

Decomposition reaction

When a molecule is broken down into smaller molecules. AB->A+B

Explain why chemical reactions in the body are often irreversible.

When products of a reaction are continuously taken away from the sight of the reaction it is unable to present for the reverse reaction. Furthermore, reaction involving energy release will not go backwards unless energy is put into them.

Explain the concept of pH.

pH measures the relative concentration of H+ in the solution. A low pH means it is acidic. A high pH means it is basic. A pH of 7 is neutral.

Atomic number

this is the number of protons in the nucleus