DNA Flashcards
What is DNA often called?
The blueprint of life
What does DNA do in simple terms?
DNA contains the instructions for making proteins within the cell?
Why do we study DNA?
-It is the central importance in all life on earth
-Medical benefits such as cures for diseases
-better food crops
where are our genes?
on our chromosomes
Chromosomes are made up of which chemical?
DNA
What is the basic shape of DNA?
DNA is a very long polymer. The basic shape of DNA is like a twisted ladder called a double helix.
what is the backbone of DNA?
Phosphates and Deoxyribose sugar
what are the “teeth” of DNA?
Nitrogenous bases
what is DNA a polymer and have many millions of?
Nucleotides.
what are the four nitrogenous bases?
Cytosine
Thymine
Adenine
Guanine
What are the two kinds of bases in DNA?
Pyrimidines and Purines
What kind of bases are Thymine and Cytosine? why.
Pyrimidines. They are single ring bases.
What kind of bases are Adenine and Guanine and why?
Purines. They are Double ringed.
What are the “rings” of the bases in DNA.
Carbon and Nitrogen atoms.
How many strands does DNA have?
Two.
Why do the nitrogenous bases attract to each other?
Hydrogen bonds.
What are there millions of in single molecules of DNA?
Hydrogen bonds.
What does Adenine always join together with?
Thymine in DNA and Uracil in RNA
What does Cytosine always join together with?
Guamine
Each cell has about how much DNA?
2 m of DNA
How many cells does the average human being have?
about 75 trillion cells
The average human being has enough DNA to go from the earth to the sun how many times?
more than 400 times.
DNA has a Diameter of only how much m?
0.000000002 m
what are the building blocks of nucleic acids?
nucleotides
What does DNA stand for?
Deoxyribonucleic acid
Where in the cell are Chromosomes located?
The nucleus
What is the sugar found in DNA?
Deoxyribose
What are the small sections of DNA molecules that determine genetic traits?
Genes
What are the Pyrimidine bases?
Thymine and Cytosine
What are the Purine bases?
Adenine and Guanine
What are the three parts of a nucleotide?
Phosphates, sugar, and the base (Adenine).
What are the “sides” of the DNA ladder made of?
Sugar-phosphate backbones
What are the “rungs” of the DNA ladder made of?
The four nitrogenous bases Thymine, Adenine, Cytosine, and Guanine.
What are the four nitrogenous bases called?
Thymine, Adenine, Cytosine, and Guanine.
What bond are nucleotides attached by?
The bond between the sugar base and the phosphate group.
What is DNA shaped like?
A double helix.
What are the steps of DNA replication
1.) Hydrogen bonds between nucleotides break
2.) strands of DNA seperate
3.) Free Nucleotides are attracted to exposed bases on the loose strands of DNA
4.) Hydrogen bonds between nucleotides form
how do you find the amount of the nitrogenous bases
each compatible base will have an equal percentage. The total sum of all of the bases will add up to 100.
n(2) + x(2)=100
what type of biological molecule is the DNA helicase
enzyme
What is the role of the DNA helicase in the replication of DNA?
to break hydrogen bonds.
What kind of replication is DNA?
semi-conservative replication
why is DNA replication called semi-conservative replication
the new DNA is built off of the old half
are the rungs of the nitrogenous “ladder” parallel or antiparallel?
antiparallel
what is the role of the DNA helicase in the replication of DNA?
to “Unzip” the double helix/break the hydrogen bonds.
what rule is used to re-join the free nucleotides to the exposed bases of the DNA?
the base-pairing rule
How does semi conservative replication help prevent mutations during DNA replication?
The old DNA serves as a guide or template so that the DNA is copied exactly by base pairing.
DNA replication involves a host of what?
enzymes and regulatory molicules.
which enzyme “proofreads” each new DNA strand, helping to maximize the odds that each molecule is a perfect copy of the original DNA.
the polymercase
What is the principal enzyme involved in DNA replication called?
the DNA polymercase
what is the Enzyme that joins the individual nucleotides together to produce a DNA molecule?
The DNA polymercase
before a cell divides, it duplicates its DNA in a copying process called what?
replication
when does the “unzipping” of the enzymes occur?
when the hydrogen bonds between the base pairs are broken and the two strands of the molecule unwind.
true or false, each strand serves as a template for the attachment of the complementary bases.
true.
Eukaryotic chromosomes contain both DNA and protein, tightly packed together to form which substance?
Chromatin
What do proteins do for the body?
They control chemical messages in the cell; direct the synthesis of carbo’s, lipids, and nucleotides; enzyme; and give the cell structure and movement.
What are the differences between RNA and DNA
-RNA uses Ribose sugars while DNA uses Deoxyribose
-RNA is single stranded while DNA is double stranded
-RNA uses Uracil instead of Thymine.
what does RNA use in place of Thymine
Uracil
What does the word Transcribe mean
Transcribe: to make a copy
How are special base sequences in DNA recognized by RNA?
special base sequences in DNA are recognized by RNA as “Start” and “Stop” signals.
What region of DNA is the “Start” sequence called
The promoter region of DNA
What happens when the RNA polymercase reaches the end or “Stop” part of genetic code for that protein?
It releases
when does the RNA polymercase release?
once it reaches the end or “Stop” part of genetic code for the protein.
what happens to Finished mRNA? (Message RNA)
it leaves the nucleus and goes to ribosomes in the cytoplasm
what is the first step of protein synthesis?
Transcription.
what are the 3 main types of RNA?
Messenger RNA (mRNA)
Ribosomal RNA (rRNA)
Transfer RNA (tRNA)
what is the second step to protein synthesis?
Translation
What does a group of 3 RNA bases make up?
a Codon
What does each codon specify?
each codons specify a particular amino acid
By matching the codon of mRNA to the anticodon of tRNA, what happens?
the correct amino acid is put in place.
what is formed between the 2 amino acids?
a peptide bond.
what is Transcription?
transcribing DNA information (gene instructions) into mRNA which can leave the nucleus and go to ribosomes in the cytoplasm.
What is the t in tRNA?
Transfer
what is the r in rRNA?
ribosomal
what is the m in mRNA?
messenger
how many types of RNA are there?
there are three
Where does DNA transcription occur?
in the nucleus.
Where in the cell does translation occur?
in the cytoplasm.
what is Translation?
The process of translating the sequence of a messenger RNA molecule to a sequence of amino acids during protein synthesis.
What is the “Start” codon?
AUG
What are the “stop” codons?
UAG, UAA, and UGA.
What are the three main stages of transcription
Initiation, elongation, and termination.
In which form of RNA is genetic information Transcribed from DNA
mRNA.
