Biology 100 Unit 10 Flashcards
the scientific study of life at the molecular level
molecular biology
Understanding molecular biology aids in the study of
- disease, bacteria, viruses
- DNA , genes, inheritance
- cancer
is the molecule that stores the information to create an organism (blue print)
DNA
the _________________ in DNA can be copied and passes on to the next generation
information stored
what are the two types of nucleic acids that can store genetic information
DNA and RNA
DNA and RNA consist on monomers called
nucleotides
What are nucleotides made of
sugar + nigtrogenous base + phosphate
What differentiate nucleotides from each other
their nitrogenous bases
What are the nucleotides in DNA
Adinine, Guanine, Cytosine, Thymine
What are the nucleotides in RNA
Adinine, Guanine. Cytosine, Uracil
What are the 2 bases that are Purines?
Adenine and Guanine AG
What are the 3 bases that are Pyrimidines?
Cytosine Uracil and Thymine
Who discovered that DNA is shaped in a double Helix and received a nobel prize for it
Watson and Crick
What are the nitrogenous base pairs
A-T and G-C
During __________, a cell’s DNA is copied completely so each new cell will have a complete set of DNA in the form of Chromosomes
the cell cycle
Each of the two original DNA strands serves as a template based on which two new strands of DNA are made by an enzyme
DNA polymerase
one of the original two DNA strands is passed on to each of the new cells in ______ _________
DNA replication
DNA is synthesized using the
parent strand as a templet
___________ break to form a single strand of DNA
H bonds
______________________ spreads from specific origins, is bidirectional adding nucleotides in each direction, once completed produces two daughter strands
DNA replication
_________________ is what controls how the organism looks and functions-its ___________________
DNA/genotype, phenotype
From one generation to the next __________ is continually replicated and passed down
DNA
Because DNA is copied and passed down we
should have simular sequences of nucleotides to our parents
a set of stored instructions that make proteins
DNA
RNA is generated from DNA from complementary base pairing
transcription
RNA is ____________________ into proteins after transcription
translated
There are about __________ genes in the human genome each of which encode a _____________
300,000, one specific protein
DNA is traanscibed
1 protein at a time
Each cell contains ________ the information to produce all proteins encoded in the entire genome
all
because cells specialize to do specific jobs, specific cells only express specific genes which code for cells only express specific genes which code for
proteins necessary for that specific cells function
The sequence of nucleotides in DNA and RNA determine
the sequence of amino acids in a protein
each protein differs by their
type of amino group and sequence of amino acids
When DNA is transcribed a
RNA molecule is produced
3 consecutive RNA nucloetides is called a
codon
codes for one of 20 amino acids
codon
the dictionary which describes which nucleotide sequence codes into which amino acid
the genetic code
for transcription: G= T= A= C=
G=A
T=A
A=U
C=G
The enzyme ________ is the enzyme which synthesizes RNA from DNA
RNA polymers
The first phase of transcription is
initiation
to begin polymerase must detect a start sequence called a
proliminator
When the enzyme encounters a promoter sequence,
it becomes attached to the DNA strand. This must occur before
RNA can be transcribed from DNA
The second phase of transcription is
elongation
during ____________more and more nucleotides are attached to the growing RNA molecule, representing an entire gene.
elongation
the third phase of transcription
termination
Near the end of each gene is a sequence of bases
called a ______________ sequence.
terminator
When the RNA polymerase reaches a terminator, it is stimulated to detach from the DNA template, and RNA synthesis stops ending transcription. This RNA is then processed into messenger RNA or mRNA by a process called _____________.
splicing
during splicing
introns are edited out and exons are spliced together
Splicing converts RNA into
mRNA
during translation, the set of instructions on an RNA molecule is converted to
an amino acid sequence.
Just as transcription was facilitated by an enzyme, translation requires the presence of
other molecules
What additional RNA molecules are needed to facilitate translation
tRNA- Transfer
rRNA -ribosomal
mRNA -Messanger
brings amino acids to the mRNA
tRNA transfer RNA
are 3 consecutive tRNA nucleotides which H- bond to corresponding mRNA codons
anticodons
each anticodon carries with it
1 amino acid
are small organelles. They are the site where amino acids are joined, and protein precursors are made.
ribosomes
each ribosome is made of
two subunits
Ribosmomes are made of
RNA
A working ribosome with all the players for translation assembled.
Translation has three phases, _____________________ _______________________
initiation
elongation
termination
have a cap and tail to help bind the ribosomal subunit.
mRNA molecules
mRNA binds to the small
ribosomal subunit, then an initiator tRNA anti codon molecule binds to the start codon (AUG) bringing with it Methionine
Intitiation
Subsequent mRNA codons attract incoming tRNA anticodons in proper sequence (in sets of 3 nucleotides per amino acid)
codon recognition
The ribosome acts as a catalyst and connects the growing amino acid tail with the amino acid on the incoming tRNA.
peptide bond formation
Empty tRNAs are released from the ribosome, incoming tRNAs switch places, and the mRNA moves down one codon.
translocation
tRNA are recharged and use ATP
wlamins acids
anticodons from tRNA bind with codons on mRNA in
- codon recognition
- peptide formation
- translocation
elongation
Elongation continues until the ribosome reaches a
stop codon
A mutation is a permanent change in the
nucleotide sequence of DNA
___________within a gene can be divided into two general categories.
Mutations
single base substitutions can alter
1 amino acid in a protein
Insertions and deletions of a_____________can cause a change in the entire reading frame
nucleotide
sources that cause mutations
mutagens
Although mutations are usually always harmful to an organism, they are considered a driving force of
diversity and variation.
are essentially, just DNA packaged inside proteins
Viruses
They aren’t considered living because they lack certain cellular mechanisms, such as growth.
Viruses
Viruses that attack bacteria are called
bacteriaphages
After infection of a bacteria, the virus enters one of two
reproductive cycles lytic or lysogenic cycles
The study of HIV which causes the Acquired Immune Deficiency Syndrome (AIDS) has significantly enhanced researchers understanding of
Viruses
HIV is a _____________, an RNA virus that reproduces by means of a DNA molecule.
retrovirus
Retroviruses copy their RNA to DNA using the enzyme ___________________.
reverse transcription
This enables the virus to incorporate is viral DNA in the host’s _______ of a human.
DNA
Overtime HIV may result in
AID’s
