Biology121 chapter 2
Terms in this set (80)
anything that occupies space and has mass
smallest unit of matter
a group of two or more atoms held together by covalent bonds
basic substance that can't be broken down
individual elements combined
are written with the reactants on the left and the products on the right
_______ are transformed into _________ through chemical reactions
corresponds to the number of protons
corresponds to number of protons plus neutrons
atoms themselves are composed of even smaller_____
have a positive charge, in nucleus, # determines the chemical element
has no charge,
# determines the isotope
have negative charge,
has little mass,
# determines the atoms ion state and chemical reactivity.
variations of an element that differ in their neutron number; less stable and may decay over time
two types: ionic bond or covalent bond
transfer one or more electrons from one atom to another
involve the sharing of one or more electrons between atoms
unequal sharing of electrons
non polar bond
equal sharing of electrons
weak by itself,
water can participate in several hydrogen bonds and get strong enough to form liquid bonds
a dissolving agent
the mixture of the solvent
tendency of molecules to stick together
contains a substance dissolved in water
runs from acidic(0) to basic (14)
pH between 0 and 7
pH between 7 and 14
chemicals that minimize changes in pH by accepting H+ ions
molecules that contain carbon bonded to other elements
are sets of atoms that are attached to carbon skeleton
large molecules with complex structures
molecules created by joining together smaller molecules
smaller molecules (amino acids)
adds a molecule of water and breaks bonds between monomers;
the reaction is how the body digest the polymers
the sum total of all the chemical reactions in an organism
Dehydration synthesis reaction
links two monomers together and removes a molecule of water
made by joining many monosaccharides together
they do not mix with water
EX: all lipids
"water loving" they mix with water
function in many roles but differ because their carbon skeleton is bent to form four fused rings
synthetic variants of testosterone
triglycerides that have NO double bonds in their carbon/hydrogen chains
type of unsaturated fat that contains an unusual bond EX: many processed food
a process that can produce trans fat
omega-3 fatty acid
known to reduce the risk of heart disease
joins amino acids
contains amino acids; chains may be joined together into a large complex
a protein that speeds up a chemical reaction without being charged itself
energy required for a chemical reaction to proceed
molecules that PREVENT enzymes from working
inhibitors bind to the active site
bind to a distant site
how do you write a chemical reaction?
with reactants on the left and products on the right
what are the 4 most important elements for living things?
oxygen, carbon, hydrogen, nitrogen,
how are ionic and covalent bonds different?
ionic bonds transfer electrons one atom to another;
covalent bonds share electrons between bonds(strongest)
how are single and double bonds different?
how are polar and non polar bonds different?
polar means there is an Uneven charge distribution. non polar is an EVEN charge distribtion
what are the unique properties of water that make it important to life?
hydrogen bond that constantly break and reform;
-frozen water floats
-water is an effective solvent
-strong resistance to change in temperature
-water molecules stick together
why are buffers important to the body?
It can help reduce changes in PH; buffers contract a drop in pH that occurs when you exercise
what is acid precipitation and why is it harmful?
What is ocean acidification and how is it affecting life in the ocean?
impact the ability of organisms to make calcium carbonate exoskeletons
Why is life carbon-based? Why is carbon important to life?
because it is able to form so many shapes, it can form chains of skeletons for a wide variety of chemical compound
What are the 4 important organic compounds for life?
carbohydrates, lipids, proteins, nucleic acids
What are carbohydrates? What are they made of?
common source of dietary energy for animals and important building blocks of plants.
ex: cellulose and glucose
What are four common carbs and how are they used by living things?
bread, potatoes, pasta, noodles, they are a source of energy
What is a phospholipid made of and why are they important to cell membranes?
made up of hydrophilic "water loving" head. and are stacked to make the a cell membrane. *
regulates what come in and out
Why is cholesterol important in the body?
-maintains fluidity in most cell membranes
-animal cells use it to synthesize lipid hormones, male and female
-produced in body or taken in from food
-helps digest fats, vitamin D
What is the difference between LDL 'bad cholesterol' and HDL 'good cholesterol'?
LDL- low density lipoprotein; levels increase through poor diet (cholesterol circulates to cells through body & can be deposited in artery wall.)
HDL- high density lipoprotein; levels increase through exercise (packets transport cholesterol to liver where it is removed from circulation & metabolized.
What is a triglyceride made of?
one glycerol joined to three fatty acid molecules; it stores energy (calories)
What is the difference between a saturated and an unsaturated fat?
saturated- NO double bonds; less healthy
unsaturated- has double bonds; more healthy
What are proteins made of? What is their general structure?
polymers made by joining many amino acids monomers together
-unique structure and shape that allows it to perform a special function
What are some of the functions of proteins?
transport, defense, structure,movement
Why is the shape of a protein important?
because the function is determines by precise amino acid sequence and SHAPE
Why are enzymes important in the body?
it speeds up a chemical reaction without being changed itself