Chapter 3- Biological molecules 3.8, 3.9, 3.10, 3.11 Flashcards
What is the role of DNA helicase?
It catalysis the reaction that breaks down hydrogen bonds between complementary base pairs.
What is the role of DNA polymerase?
It catalysis the formation of phosphodiester bonds between free nucleotieds and exposed bases on the tenplate strand of DNA.
What is meant by semi-conservatice replication?
DNA replication that ends in oe old strand and one new strand present in each daughter DNA molecule.
What are the main 3 stages of semi-conservative replication? (summarised)
- DNA helicase causes DNA strands to seperate
- free nucleotides will pair with complementary bases exposed strands
- these bases are then joined together by DNA polymerase
What directions does DNA polymerase travel in?
3’ to 5’ direction
What is the genetic code?
Sequences of bases in DNA are code for the sequence of amino acids in the production of proteins?.
What is a codon?
Sequence of three bases
A codon codes for an ……
amino acid
What is the start codon?
ATG
What are the two parts of protein synthesis?
TRanscription (DNA copied into mRNA) and translation (mRNA is decoded by tRNA into amino acids to make a protein)
What are the stages of transcription?
what are the stages of translation?
What do cells need energy for?
synthesis, transport, and movement
What does ATP stand for?
Adenosine triphosphate
What makes up an ATP molecule?
a nitrogenous base (adenine_, a pentose sugar, and three phosphate groups
How does ATP release energy? (reaction and equation)
hydrolysis reaction-
although small amount of energy is needed to break weak bond between last phosphate, a large amount of energy is released when bond is broken
ATP + H20 ———-> ADP + Pi (inorganic phosphate) + energy
How is energy stored as ATP?
Condenstation reaction happens which turns ADP + P into ATP.
This procces is called phosphorylation
Why is ATP a good energy source?
- small- moves eaily in and out of cells
- water soluble
- realises energy in small quantaties- heat not watsed
easily regenerated
What are some example of nucleic acids?
DNA and RNA (Large molecules discovered in cell nuclei)
What elements do nucleic acids contain?
Carbon, hydrogen, oxygen, nitrogen and phosphorus
What components make up nucleic acids?
a pentose sugar, a phosphate group, and a nitrogenous base
What are the names of the 4 bases?
Thymine
Adenine
Cytosine
Guanine
What are pyrimidines?
(Structure and name of bases)
Smaller bases, contain single carbon structures
Thymine and cytosine
What are purines?
(Structure and name of bases)
Larger bases, contain double carbon ring structures
Adenine and Guanine
