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Bio Test #2

Terms in this set (90)

Johannes Miescher
Determined that DNA is not a protein rich in nitrogen and phosphorus
Essential properties of hereditary material
1- a full complement of hereditary info must be transmitted
2-each cell should have the same amount
3-must be exempt from change
4- must be capable of encoding a massive amount of info
DNA
A polymer of nucleotide, each with a five carbon sugar, three phosphate groups and 1/4 nitrogen containing bases
Nitrogen Bases
A (adenine) T (thymine)
G (guanine) C (cytosine)
Double Helix
Two nucleotide chains/strands running in opposite directions
Chromosome
A structure that consists of DNA and associated proteins that carries part or all of a cells genetic info
Histone
a type of structure that organizes eukaryotic chromosomes
Diploid
Having two of each chromosome
Autosome
A chromosome that is the same in males and females
Step 1 of replication
Enzymes begin to unwind and separate the strands
Step 2 of replication
Primers base-pair with the exposed DNA
Step 3 of replication
Starting at primers, DNA polymerases assemble new strands of DNA from nucleotides using the parent strand as templates
Step 4 of replication
DNA ligase seals any gap that remains between bases of the 'new' data
Mutation
permanent changes in the nucleotide sequence that cannot be fixed, will be passed on and can form anywhere
Diffusion
Movement of molecules from high to low concentration
Rate of diffusion depends on (5)
Size
Temperature
Concentration
Charge
Pressure
Hypotonic
Having a lower concentration (inside) of solute than another solution (outside)
Hypertonic
Having a higher concentration (inside) of solute than another solution (outside)
Turgor
Water pressure within a cell
Passive transport
Solutes through a membrane that requires no energy; transports proteins and carrier proteins
Active transport
Solutes through a membrane that requires energy (ATP)
Exocytosis
Process by which a cell releases large amounts of material
Endocytosis
A process in which a cell takes in a small amount of cellular fluid
Phagocytosis
A type of endocytosis in which a cell engulfs large particles or whole cells such as microbes or cellular debris
Transcription
DNA to RNA, enzymes use the gene's DNA sequence
Ribosomal RNA (rRNA)
part of structure of ribosomes, assemble amino acids into peptide chains
Transfer RNA (tRNA)
delivers amino acids to ribosomes during protein synthesis
Messenger RNA (mRNA)
contains protein building message, specifies order
Translation
Process by which mRNA is decoded and a protein is produced
Energy
The capacity to do work
Kinetic energy
Energy in motion
First law of thermodynamics
Energy cannot be created or destroyed
Entropy
Measure of how much the energy of a system is dispersed; hot to cold until equal
Second law of thermodynamics
When energy is changed from one form to another, some useful energy is always degraded into lower quality energy, usually heat (spreads out spontaneously)
Potential energy
Stored energy
Products
A molecule that is produced by a reaction
Reactants
A molecule that enters a reaction and is changed by participating in it
Endergonic
A chemical reaction that requires the input of energy in order to proceed
Exergonic
A chemical reactions that release energy
Activation energy
Energy needed to get a reaction started
Metabolism
A set of chemical reactions through which an organism builds up or breaks down materials as it carries out its life processes
Catalysis
The acceleration of a reaction rate by a molecule that is unchanged by participating in the reaction and increases reaction time; some are RNA's most are proteins
Substrate
of an enzyme, a reactant that is specifically acted upon by the enzyme
Active sites
Pockets wehre substrates bind and where reactions proceed; complementary in shape, size, polarity and charge to the enzymes substrate
Transition state
A breaking point where reactions can run without additional energy input; lowers activation energy
Ways to increase reaction time (4)
Forcing substrates together
Orienting substrates
Inducing fit
Shutting out water
Metabolic Pathway
Series of enzyme-mediated reactions by which cells build, remodel or breakdown an organic molecule; some linear and some cyclical
Allosteric regulation
A regulatory substance that binds outside of the active site and alters the shape
Feedback inhibition
Decreases or stop activity
Redox reaction
One molecule accepts electrons (it becomes reduced) from another (reduction)
Electron transfer chain
Enzymes and other molecules that accept and give up electrons in sequence, releasing energy in steps
Cofactors
A metal ion to organic compound that associates with an enzyme and is necessary for its functions; stabilizes the structure on an enzyme
Coenzymes
An organic cofactor that transfers electrons
Heme
Small compound with an Iron atom at the center
Antioxidants
Reduces the amount of damage that cells sustain as a result of oxidants
ATP/ADP cycle
ADP forms when a phosphate group is removed from ATP. ATP forms when a phosphate group is added.
Influences on the movement of Ions and Molecules (5)
Size
Temperature
Concentration
Charge
Pressure
Tonicity
Solute concentration of one fluid relative to another separated by a membrane
Isotonic
Identical solute concentration
Osmosis
Hypotonic to hypertonic
Osmotic pressure
Amount of tutor that prevents osmosis into cytoplasm or other hypertonic fluid
Facilitated diffusion
Changes shape when binding to a glucose
RNA polymerase
Adds nucleotides at the end of growing RNA
Promoter
A sequence to which RNA polymers bind
Introns
sequence that intervenes between exons; removed during post transcriptional modification
Exons
sequence that stays in the RNA after post transcriptional modification
Alternative splicing
Post mod process in which some eons are removed or joined in various combinations
Codon
a nucleotide base triplet that codes for amino acid or stop signal during translation
Genetic code
Complete set of 64 mRNA codons
AUG
Signal to start DNA change
Stop codons
UAA, UAG, UGA
Anticodon
group of three bases on a tRNA molecule that are complementary to an mRNA codon
Base pair substitution
a gene mutation in which one base pair in a DNA sequence is replaced with a different pair
Deletion
A change to a chromosome in which a fragment of the chromosome is removed.
Insertion
A mutation where one nucleotide inserts itself into an existing strand; can cause a frameshift
Anemia
A condition in which the blood is deficient in red blood cells, in hemoglobin; mutation in the alpha or beta globin
Sickle cell anemia
A human genetic disease of red blood cells caused by the substitution of a single amino acid in the hemoglobin protein; it is the most common inherited disease among African Americans.
Beta thalassemia
Deletion of beta globin genes
DNA cloning
Set of methods that uses living cells to make identical copies of a DNA fragment
Restriction enzyme
cuts DNA wherever a specific nucleotide sequence occurs
Recombinant DNA
molecule containing genetic material from more than one organism
Cloning vector
A molecule that can accept forge in DNA and be replicated
CDNA
Complementary DNA that uses RNA as a template using reverse transcriptase
Reverse transcriptase
A replication enzyme
Genome
All the genetic information in an organism; all of an organism's chromosomes.
DNA Libraries
collections of restriction fragments cloned within suitable host cells
Probe
A fragment of DNA or RNA labeled with a tracer
Polymerase chain reaction
A method of producing thousands of copies of DNA segment using the enzyme DNA polymerase; uses hear to separate strands and cooling allows primers and template formation
Electrophoresis
A process where DNA fragments are separated according to size using electrical charges
Human Genome Project
A project coordinated by the National Institutes of Health (NIH) and the Department of Energy (DOE) to determine the entire nucleotide sequence of the human chromosomes
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