nucleic acids- lecture #5 (not the whole thing) Flashcards
what does ATP stand for
adenosine tri-phosphate
what is ATP considered to be?
the energy currency of the cell
what is the organic molecule in ATP?
adenosine
what is adenosine composed of?
adenine and ribose sugar
what is adenosine attached to in order to create ATP?
3 phosphate groups via high energy covalent bonds
in order to release energy what can be cleaved off the ATP?
inorganic phosphate
what are the 4 main groups of organic molecules?
carbohydrates, lipids, proteins and nucleic acids
what builds macromolecules?
monomers build polymers
polymers build macromolecules
what do monomers consist of?
individual units of the molecules
(individual blocks of lego)
what are polymers considered to be?
very diverse molecules
what can polymers be made out of?
protein or DNA
how do monomers build polymers to make macromolecules?
monomers bond with an identical and similar types of monomers, form a larger, macromolecule known as a polymer.
are all polymers assembled the same way?
yes
how is assembly and breakdown made possible of polymers?
through the use of enzymes
what are enzymes?
protein polymers that increase the rate of reactions
polymer synthesis and breakdown
all polymers are assembled the same way
polymers are broken down by adding water across a covalent bond
what is the process of a dehydration reaction?
- removes a water molecule
- one molecule donates an H+
- one donates an OH-
- because they’re alone they hold hands and create their own molecule
the process of dehydration of reaction builds what and produces what?
builds polymers and produces water
what is a hydrolysis reaction?
chemical reaction that breaks apart a larger molecules by adding water molecule
a hydrolysis reaction is catalyzed by what?
enzymes
how we digest food
carbohydrates include ______ and _____ ________
sugars and sugar polymers
what is a monosaccharide a type of?
monomer
what is the most common monosaccharide?
glucose
what do all sugars consist of?
a carbonyl group and many hydroxyl groups
what is a carbonyl group and hydroxyl group chemical equation?
carbonyl: C=O
hydroxyl: -OH
how do you know if the sugar is ketose or aldose?
the location
see brainscape folder
what is an example of an aldose sugar?
glucose
what is an example of a ketose sugar?
fructose
sugar names generally end is what suffix?
‘ose’
the size of the carbon skeleton may be used as a basis of classification, what is a 3 carbon framework for sugar called?
triose
what is a 4 carbon sugar called?
tetrose
what is a 5 carbon sugar called?
pentose
what is a 6 carbon sugar called?
hexose
glucose is often depicted as a linear molecule, in solution it is most commonly found in what structure?
cyclical structure (hexagon shape)
what are sugars used for? (2)
fuel source in the cell
to assemble other complex molecules
if sugar is not used in what reaction, the sugar will be stored as _________ or _____________
if sugar is not used in dehydration reactions, the sugar will be stored as disaccharides or polysaccharides
polysaccharides are macromolecules that consist of how many monomers?
100, 000 monomers covalently linked via glycosidic bonds
what are polysaccharides function? (2)
storage molecules that can be broken down when the cell needs energy
others form cell wall material
the cell wall that some polysaccharides create is exterior to what cells?
fungal and plant cells
what does bond position determine in polysaccharides?
architecture and polysaccharide function
what do plant and animal cells store for later use?
sugars
what does the plant store in form of glucose?
starch
where do plants store the granules in the plant cell?
inside of structures called plastids
when energy is needed what releases glucose from the starch?
hydrolysis
what do animal cells need to hydrolyze starch?
enzymes
what is an amylose?
unbranched starch
what is amylopectin?
branched starch (includes 1-6 linkages)
in animal cells what is the storage polymer for glucose?
glycogen
is glycogen more or less branched as amylopectin?
more branched
where is glycogen stored?
in human liver and muscle cells
when the cell needs energy what happens to hydrolysis of glycogen?
hydrolyzed at an increased rate
structural carbohydrates include cellulose which is a major component of what?
plant cell wall
glucose exists in what two ring structures?
alpha and beta
in starch, are glucose monomers alpha or beta?
alpha
in cellulose, are glucose monomers alpha or beta?
beta
what is the difference between alpha and beta?
alpha hydroxyl group points down
beta hydroxyl group points up
why do only plants have cellulose?
because cellulose contains beta, beta needs different enzymes to hydrolyze beta linkages and animals do not have the enzyme to cut beta linkages
what is used as a polysaccharide component of fungal cell walls?
chitin
what are lipids not formed by?
repeating monomers
what diverse group do lipids include? (3)
fats, phospholipids and steroids
are lipids hydrophilic or hydrophobic?
hydrophobic
what are examples of lipids?
fats, oil (triglycerides)
in what form do we store extra energy?
fats
how are fat molecules assembled?
via dehydration reactions
what forms the neck of the structure in fats?
glycerol sugar
how are fatty acid tails attached to glycerol?
ester linkages (can be 1, 2, or 3) fatty acids attached
what are fatty acids composed of?
Carboxylic acid and a non-polar tail
how is triacylglycerol (triglyceride) formed?
when 3 fatty acids are attached to the glycerol neck
what do triglycerides do?
store energy, insulate us and protect our vital organs
what are saturated fats? what are their properties? (3)
don’t have any double bonds
allows for tight packing (doesn’t have kink in tail)
but solid fats at room temperature
what are unsaturated fats? (3)
contain one or more double bonds
liquid at room temperature
creates a kink in the chain
are fats saturated or unsaturated?
they can be saturated or unsaturated
how do we get our omega-3 fatty acids?
through consumption/ diet
the body cannot synthesize omega- 3 fatty acids in the body
what is used in the body for energy storage?
fats
One gram of fat stores ____ as much energy as ___ gram of sugar
twice as much energy as one gram of sugar
what do fats protect against?
organs and provides insulation
where are phospholipids a major component?
cell membrane
what is a phospholipid made of?
2 fatty acids are attached to a glycerol molecule which is attached to a phosphate
are phospholipids hydrophilic or hydrophobic?
hydrophobic tails (non-polar)
hydrophilic head (polar)
what does amphipathic mean?
polar and non-polar at the same time
what is steroids carbon skeleton structure?
4 fused rings
what does a steroid include?
include vertebrate sex hormones and cholesterol
what is the workhorse of the cell?
proteins
what do proteins function as? (7) TESS CcDmM
transport
enzymes
storage
structure
cell communication
defense molecules
movement
how many proteins are there?
thousands
what are proteins made of?
one or more polypeptides associated with one another
how are polypeptides constructed?
from a unique combination of amino acids
how many different amino acids are there?
20
what dictates the amino acid sequence of the protein?
DNA sequence
how are amino acids attached to one another?
dehydration reaction forming a covalent bond (peptide bond)
amino acids are the monomers of polypeptide structures, what do they consist of? (3)
Consist of a centrally located carbon atom: the alpha carbon
Consist of a carboxylic acid terminus (COO-)
Consist of an amino terminus (NH3+)
what are the 4 different groups of amino acids based on?
the type of R group present
what are the 4 different groups of amino acids?
Non-polar, hydrophobic
Polar, hydrophilic
Acidic, hydrophilic
Basic, hydrophilic
what do acidic amino acids do?
donate protons in solution becoming anionic (-)
what do basic amino acids do?
accept protons in solution becoming cationic (+)
what terminus do all polypeptides consist of?
amino terminus and a carboxyl terminus
what out numbers the two termini (amino and carboxyl)?
the number of side chains (R groups)
what is an R group?
side chain (normally attached to alpha carbon)
can be many different forms (polar, non-polar, aeronamic…)
what is an alpha carbon?
carbon in the middle attached to the R group
what determines the ‘personality’ of the protein?
chemical nature of the R group
what are the 4 different levels of structure of a protein?
primary structure
secondary structure
tertiary structure
quaternary structure
what is the primary structure?
amino acid sequence of the protein
how is the secondary structure made?
hydrogen bonds twist the polypeptide into a coil (alpha helices) or sheet (beta-pleated sheet)
how is tertiary structure formed?
formed due to the chemical interactions between R groups in the secondary structure and individual proteins
when the hydrogen twists, all the R groups are exposed, causing them to attract or repel each other
what bonds form in the tertiary structure?
disulfide bonds form between S of cysteine amino acids in the polypeptide chain
how is the quaternary structure formed?
two or more polypeptides come together to form a functional molecule
why might protein structure be affected?
by salt concentration
temperature
pH
what is the protein structure being affected referred to as?
denaturation
leads to a loss of protein function
*****what encodes the primary amino acid sequence of a protein?
genes
what are genes made of?
DNA
what does DNA do and what needs to happen to DNA for a protein to be assembled?
DNA carries information needed to make proteins but it needs to be converted into RNA before a protein can be assembled
what is the length of nucleic acids?
the length ranges from long to very long in length, this makes nucleotide combinations infinate
what does each nucleotide consist of?
a five carbon sugar (deoxyribose or ribose)
a phosphate group
a nitrogenous base (purine or pyrimidine)
what is a purine and a pyrimidine and what is the difference?
purine: adenine and guanine (double ringed structure)
pyrimidine: cytosine and thymine (DNA)
cytosine and uracil (RNA)
(pyrimidine is single ringed structure)
how are nucleic acid polymers joined to one another?
they’re joined to one another by covalent bonds via dehydration reactions
what is the structure of nucleic acids?
nucleic acids are formed using a phosphate sugar backbone. each phosphate is connected to a sugar and a nucleotide monomer
RNA only consists of this strand (single stranded) it makes it less stable
what is the structure of DNA?
DNA is always double stranded (found as a double helix) 2 nucleotides wrapped
stores information during protein synthesis
nitrogenous bases on one strand always pair with nitrogenous bases on the other strand by connecting A=T and C=G through hydrogen bonds anti parallel
cytosine and guanine are harder to break apart because they have 3 hydrogen bonds connecting them
what is found in equal quantities in molecule of DNA?
adenine and thymine
