Biology Chapter 2 Flashcards
What is an Atom
The smallest known unit of measurement, it cannot be made or destroyed
What does an atom contain?
A nucleus with neutrons and protons, and electrons circling around.
proton versus electron
protons are positively charged, electrons are negatively charged
What is an Element
a pure substance made up of only one type of atom
How many naturally occurring elements are there?
92
atomic number
how many protons there are in the atom, this is shown in the top left corner of the element in the periodic table.
atomic mass
the number of protons plus the number of neutrons
What is a chemical compound
substance made of two or more atoms from elements
What are the types chemical bonds
covalent, ionic, and hydrogen
what is a covalent bond
a bond made by sharing electrons
What is an ionic bond
a bond made by transferring electrons
What is a hydrogen bond
a bond made between polar molecules, one is positively charged and one is negatively charged so they attract
polar versus non-polar molecules
polar molecules have an unequal distribution of electrons and therefore have a different charge in different parts
compound versus molecule
a compound is the JOINING of the atoms in elements, a molecule is a group of atoms held together by a covalent bond
van der wals forces
Weak attractions when molecules are close together
What are two unique properties of water?
Storage of energy (moderates earths temp.)
Cohesion and Adhesion (water attracts to both itself an d other substances
cohesion versus Adhesion
Cohesion is the attraction of a molecule to itself, adhesion is the opposite
Solution versus Mixture
A solution occurs when molecules are equally distributed with one another
solute versus Solvent
The solute is dissolved in the solvent
Why is water a nearly universal solvent?
Because of its polarity it can easily break apart any polar molecules
What happens when water bonds break
Occasionally hydroxide (OH-) or hydrogen (H+) ions are formed
Acid versus Base
An acid has an increased number of H+ ions, a base has an increased number of OH- ions.
What does pH stand for
Power of Hydrogen
What is a buffer and what is it used for
weak acids/bases that prevent sudden changes in pH
What are Organic Compounds
Carbon based compounds found in any living thing
What are Monomers and Polymers?
Monomers are the building blocks of polymers (it is a general term)
Which of the 5 key classes of organic compounds are not polymers?
lipids
lipids
a fatty organic compound that is non polar and doesn’t dissolve in water
unsaturated versus saturated fats
unsaturated fats have a double carbon bond and there for have a break in the chain, this causes them to be more liquid.
carbohydrates
organic compounds made of carbon, hydrogen, and oxygen in a 1:2:1
what are monosaccharides?
The single sugar building blocks of carbohydrates, there are also disaccharides, and polysaccharides
what are some carbohydrate molecules that store energy?
starches (plants)
glycogen (animals)
what are some carbohydrate structural molecule?
cellulose (plant)
chitin (animals)
protiens
large polar molecules made up of amino acids
what codes for protiens?
DNA
Nucleic Acid
DNA/RNA, chain of smaller molecules called nucleotide
What are the three parts of a nucleotide?
a sugar, a base, and a phosphate group
What is Energy
The ability to move or change matter
How is energy affected by chemical reactions?
It is either stored or released
endergonic versus exergonic reactions
endergonic reactions happens when energy is absorbed, exergonic is when energy is released
How does a catalyst help a chemical reaction
It lowers the activation energy needed, one type is an enzyme used in biochemical reactions
what is a biochemical reaction
one that happens in a cell
What factors affect enzymes?
pH and temperature
(in some cases increased temperature makes the reaction even faster but to much heat causes the enzyme to die)
where does the substrate go to become a product
The active site
How do you test for starches?
iodine- dark blue
How do you test for protiens?
Biuret- purple
How do you test for lipids?
Sudan 3- hot pink layer
How do you test for nucleic acids?
diphenylamine- blue/purple/green
