Chapter 2 Flashcards
What is an Ion? And how are they written?
An atom that gave up or gained an electron. written with the chemical symbol and (+) or (-) indicating its charge
What is a molecule? And how are they written?
Molecules are formed when atoms share electrons. And they are written as a molecular formula showing the number of atoms of each element (H2O)
What are chemical bonds?
The force of attraction that holds atoms of a molecule together
What is a valence shell?
The number of electrons in its outermost shell
How does a atom decide how it will bond with another atom?
The likelihood that an atom will form a chemical bond with anther atom depends on the number of electrons in its outermost shell
What are other types of chemical bonds?
- Ionic bonds
- Covalent Bonds
- Hydrogen Bonds
What is a ionic bond?
When an atom loses or gains a valence electron, ions are formed
What kind of charged ions are attracted to each other?
Positively charged ions and negatively charged ions are attracted to one another
What is Cation?
Positively charged ions that have given up one or more elections (electron donors)
What is a Anion?
negatively charged ions that have picked up one ore more electrons that another atom has lost (electron acceptors)
What is a covalent bond?
Covalent bonds are formed by the atoms of molecules sharing one, two, or three pairs of their valence electrons
What kind of bonds are the strongest chemical bonds in the body?
Covalent bonds
Can covalent bonds be nonpolar and polar?
Yes, in a nonpolar covalent bond, atoms share the electrons equally; one atom does not attract the shared electrons more strongly than the other atom
What is a polar covalent bond?
Formed by the unequal sharing of electrons between atoms
What is a example of a polar covalent bond?
Water molecules.
In a water molecule, oxygen attracts the hydrogen electrons more strongly. Oxygen has greater electronegative as indicated by the negative Greek delta sign
What is a hydrogen bond?
A weak bond between two molecules resulting from an electrostatic attraction between a proton in one molecule and a electronegative atom in the other
Are hydrogen bonds as strong as covalent bonds?
They are approximately 5% as strong
What are inorganic compounds?
Structurally simple molecules that usually lack carbon
What are organic compounds?
Molecules that
1. Always contain carbon
2. always have covalent bonds
3. usually contain hydrogen
4. usually are large molecules
What is the most important and abundant inorganic compound in all living systems?
Water
What is waters most important property?
The polarity of the water, which enables reactants to collide to form products
What is a Solvent?
In a solution the solvent dissolves in the solute
What does hydrophilic mean?
When substances which contain polar covalent bonds and dissolve in water
What does hydrophobic mean?
substance which contain non-polar covalent bonds
Is waters heat capacity high or low?
it is high, It can absorb or release a relatively large amount of heat with only a modest change in its own temperature
Why can water change its temperature so fast?
The high number of hydrogen ions in water
Is waters capacity for vaporization high or low?
It is high. The amount of heat needed to change from liquid to gas requires a large amount of heat.
What are 3 common mixtures?
- Solutions
- Colloid
- Suspension
What is a solution?
A substance in which the solvent dissolves another substance called the solute. Usually there is more solvent than solute in a solution
What is a colloid?
Differs from a solution mainly on the basis of the size of the particles with the particles in the colloid being so large enough to scatter light
What is a suspension?
The suspended material may mix with the liquid or suspending medium for some time, but it will eventually settle out.
What is range of the pH scale?
0-14
What is a neutral pH
7 (water)
What is a acidic pH?
pH below 7
What is a basic pH?
pH above 7
pH is on what kindof scale?
logarithmic scale
What is a buffer system?
a solution that resists change in pH when acids or bases are added to it.
What do buffer systems accomplish?
Changing strong acids and bases into weak acid and bases
What are carbohydrates?
They provide most of the energy needed for life and include sugars, starches, glycogen, and cellulose. Other carbs can function as food
Can carbohydrates be converted to other substances?
Yes they can be converted into other substances which are used to build structures and to generate ATP
What are the 3 main group of carbs based on their size?
- Monosaccharides
- disaccharides
- Polysaccharides
What are lipids?
Like carbs, contain carbon, hydrogen and oxygen; unlike carbs, they do not have a 2:1 ratio of hydrogen to oxygen
Do lipids have polar covalent bonds?
They have a few polar covalent bonds
If Lipids have few polar bonds, what does that mean?
It means that they are hydrophobic and that they are mostly insoluble in polar solvents like water.
What are lipoproteins?
They combine with proteins to transport blood
What are proteins?
constructed from combinations of 20 amino acids. And they are the building block for building tissue
What are dipeptides?
They are formed from 2 amino acids joined by a covalent bond called a peptide bond
What are polypeptide chains?
Formed from 10 to 2000 amino acids
What are the levels of structural organization for protein?
- primary
- secondary
- tertiary
- quaternary
What does the resulting shape of the protein influence?
Its ability to recognize and bind to other molecules
What is denaturation?
when a protein is in a hostile environment and causes it to lose its characteristic shape and function
What is DNA?
forms the genetic code inside each cell and thereby regulates most of the activities that take place in our cells throughout a lifetime
What is RNA?
RNA relays instructions from the genes in the cell’s nucleus to guide each cells assembly of amino acids into proteins by the ribosomes
What are nucleic acids?
huge organic molecules that contain carbon, hydrogen, oxygen, nitrogen, and phosphorus
What are the basic units of nucleic acids?
Nucleotides, composed of a nitrogenous base, a pentose sugar, and a phosphate group
What is ATP
Adenosine triphosphate: Temporary molecular storage of energy as it is being transferred from exergonic catabolic reactions to cellular activities
What is hydrolysis of ATP?
The removal of terminal phosphate group by enzyme. Which release energy and leaves ADP ( adenosine diphosphate)
