Bio Ch 2 and 3 Flashcards
What is cohesion
the tendency of molecules of the same kind to stick together - this is strong in water bc of H bonds
what is an example of cohesion
trees use it to transport water and nutrients from their roots to their leaves
what is adhesion
the clinging of one substance to another
what is an example of adhesion
the adhesion of water to the cell walls of a plant’s thin veins helps counter the downward pull of gravity
what is surface tension
a measure of how difficult it is to break the surface of a liquid
describe water’s surface tension
unusually high
why does water have a high surface tension
bc of its ability to h bond
what abilities does h bonding give to water
- strong cohesion
- strong adhesion
- high surface tension
- stronger resistance to temperature change
- less dense as solid than liquid
how does h bonding give water a strong resistance to temperature change
heat must be absorbed to break h bonds and heat must be released to make h bonds - thus, it takes a lot of energy (heat) to raise water even a few degrees
what is evaporative cooling
when a substance changes from a liquid to a gas, the surface of the liquid that is left behind (not evaporated) is cooler - this happens bc the hottest molecules are the ones that have enough energy to evaporate
what is a solution
a liquid of a uniform mixture of two or more substances
what is a solvent
dissolving agent (usually water)
what is a solute
a substance that is dissolved
what is an aqueous solution
one where water is the solvent
what is an acid
a compound that donates H+ to solutions
what is a base
a compound that accepts H+ ions
what are buffers
substances that resist change in pH by accepting or donating H+
what is acid precipitation
precipitation with a pH less than 5.2
what is ocean acidification
CO2 dissolving in seawater lowers ocean pH
most of the unique properties of water result from the fact that water molecules are…
polar and form h bonds
Why do water molecules form h bonds
H2O molecules are polar, with oxygen pulling the electrons closer to it, leaving each H feeling very positive. These positive H’s want something negative, so they look for the most electronegative elements, N, O , or F. Water can h bond with itself bc it has both H and O
what are two ways that the water in your body helps stabilize your body temp
evaporative cooling and h bonds make the water in your body resistant to temp change bc it takes a lot of energy to break h bonds and increase temp
what are organic compounds
carbon-based molecules
what is a hydrocarbon
compounds composed of only H and C
what is the chain of carbons in an organic mlc called
a carbon skeleton
what is an isomer
compounds with the same formula but different structural arrangements
what is hydrophilic
water-loving
what is a hydroxyl group
consists of a hydroxide ion
what is a carboxyl group
a carbon atom is double bonded to an oxygen atom and bonded to a hydroxyl group
acts as an acid by contributing H+ to a solution and becomes ionized
what is a carbonyl group
a carbon atom double bonded to an oxygen atom
what is an amino group
a nitrogen bonded to two hydrogens and the carbon skeleton
acts as a base picking up an H+ from solution
what is a phosphate group
consists of a phosphorus atom bonded to 4 oxygen atoms
usually ionized and attached to the carbon skeleton by one of its oxygens
what is a methyl group
consists of a carbon bonded to 3 hydrogens
what are the 4 main classes of molecules
carbohydrates, lipids, proteins, and nucleic acids
what are macromolecules
giant molecules made by joining smaller molecules into chains called polymers
what is a polymer
a large molecule consisting of many identical or similar building blocks strung together
what is a monomer
a building block of polymers
How do monomers form polymers
dehydration
what is a dehydration reaction
a reaction that removes a molecule of water
how do your cells break polymers into monomers
hydrolysis
what is hydrolysis
a reaction that adds a molecule of water
what are enzymes
specialized macromolecules that speed up chemical reactions in cells
what are the 4 common characteristics of organic molecules
- all carbon based
- formed from a few elements joined together into small molecules which join together into big molecules
- built from a single type of building block
- their form determines their function
what is the building block of carbohydrates
a single sugar
what are the carbohydrate monomers
monosaccharides (single-unit sugars)
are monosaccharides hydrophilic or hydrophobic
hydrophilic
what are the 3 main sugars all carbohydrates are made of
fructose, glucose, and galactose
what is special about glucose and fructose
they are isomers
what is a disaccharide
2 monosaccharide monomers joined together by dehydration
what are some examples of disaccharides
lactose (combo of glucose and galactose)
sucrose (combo of glucose and fructose)
maltose (combo of 2 glucose)
what are the elements contained in carbohydrates
carbon hydrogen oxygen
what does a monosaccharide look like
a ring
what are simple sugars
mono and disaccharides
what are simple carbohydrates
mono and disaccharides
what do simple carbohydrates do
raise glycemic index quickly and higher
what is glycemic index
measures sugar in your blood and your insulin response
what are some high GI foods
corn, doughnuts, popcorn, soda
what are some medium GI foods
ice cream, mangos, bread
what are some low GI foods
apples, bananas, milk
is glucose les evil than fructose?
jury is still out, but the overconsumption of sugar or HFCS along with dietary fat and decreased physical activity do contribute to weight gain
What is a polysaccharide
more than 2 monosaccharides joined together
what are the 3 main types of polysaccharides
starch, glycogen, and cellulose
what is starch made of
entirely of glucose monomers; also has a helix shape
what is the job of a starch
used in food storage in plants
what is the job of a glycogen
food storage in animals; branched
what is cellulose used for
structural support in plants; cannot be digested by animas (fiber)
unbranched; held together by H bonds
how do sugar substitutes work
bind to receptors on the tongue and trick the brain into thinking they are sweet
what are some examples of sugar substitutes
aspartame, saccharine, sucralose, neotame
what are complex carbs
polysaccharides; slower and lower GI response
are lipids hydrophobic or hydrophilic
hydrophobic
what do lipids mainly consist of
carbon and hydrogen atoms linked by non polar covalent bonds
what is the function of lipids
long term storage of energy in the body
what is the building block of lipids
fatty acid
what are the 3 types of lipids
fats, phospholipids, and steroids
what is a fat
a large lipid made from fatty acids and glycerol
what are the 3 different kinds of fats
unsaturated, saturated, and trans
what are the characteristics of unsaturated fats
has double bonds, so less hydrogens –> prevents fats from packing together and solidifying at room temp, healthier
what are some examples of unsaturated fats
corn oil, vegetable oils, olive oils
what are the characteristics of saturated fats
no double bonds –> pack closely together, making them solid at room temp, not healthy
what are some examples of saturated fats
most animal fats, butter
what are trans fats
unsaturated fats but behave like saturated fats
what are phospholipids
major components of cell membranes; contain phosphorus and 2 fatty acids
what is the difference between phospholipids and fats
P has 2 fatty acids attached to glycerol instead of 3
what is arteriosclerosis
Build up of fat in the form of plaque on the walls of your arteries (Saturated and trans fats)
what are waxes
consist of a fatty acid and an alcohol (cover fruit to protect them)
what are steroids
lipids that consist of 4 fused rings; cholesterol used to make other steroids
what are anabolic steroids
synthetic variants of the male hormone testosterone
what do anabolic steroids do
build up muscle and bone mass
what can steroid abuse do
lead to rage, heart disease, infertility, cancers, and depression
what is THG
steroid drug that went undetected by the urine test
what is the function of proteins
form muscles, transport O2, act as hormones and enzymes, determine how our bodies look and function
what is the building block of proteins
amino acids
what is the name of the bond that joins amino acids
peptide bond
what is it called when groups of amino acids are joined together
an protein
how many different amino acids are there
20
what are all amino acids made of
an amino group and a carboxyl group
what makes one amino acid unique from any others
the “r” group
what does the r group in an amino acid determine
the specific properties - the shape and function, whether it will be hydrophobic or hydrophilic, etc
what is it called when 2 amino acids join together
a dipeptide
what is a chain of amino acids called
a polypeptide
what is a protein
one or more polypeptide chains precisely coiled, twisted, and folded into a unique, 3 dimensional shape
what is denaturation
proteins lose their shape and unravel depending on changes in
pH
Salt concentration
temperature
what is important about protein shape
Must have the correct shape to react with a particular molecule to cause a reaction
what are the 4 shapes of proteins
Primary-straight chain sequence of aa
Secondary-coils in either and alpha helix or pleated sheet formation
Tertiary-3D has both alpha helix and pleated sheets
Quartenary-two or more polypeptide chains
what could happen if proteins fold incorrectly
alzheimers, parkinsons
what are the building blocks of nucleic acids
nucleotides
what are the two types of nucleic acids
DNA and RNA
what is the role of DNA
contains instructions on how to make proteins
what is the role of RNA
makes a copy of the DNA strand and carries it to the protein-building machinery of the cell
what are the 3 parts to nucleic acids
5-carbon sugar, a phosphate group, a nitrogenous base
what are the 4 types of nitrogenous bases in DNA
Adenine
Thymine
Cytosine
Guanine
what are the 4 nitrogenous bases in RNA
Adenine
Cytosine
Guanine
uracil
what is the backbone of DNA/RNA made of
an alternating sugar-phosphate backbone - the nitrogenous bases go in the middle and connect each backbone
what shape is RNA
a single polynucleotide strand
what shape is DNA
a double helix
which nitrogenous bases pair together in DNA
A-T, C-G
which nitrogenous bases pair together in RNA
A-U, C-G
