Science Chpt. 13 Flashcards
(21 cards)
What makes up nucleotides?
5 carbon sugar - deoxyribos
phosphate group -
nitrogenous base - AGTC
What is base pairing?
hydrogen bonds form between A-T and G-C
Are hydrogen bonds durable?
They are weak in order for them to break for replication.
which nucleotides pair together
A-T
G-C
A-U
What holds the bonds between nucleotides?
Hydrogen bonds
Where is DNA in a Prokaryotic cells?
in the cytoplasm
where is DNA in a eukaryotic cell?
In the nucleus
Why do DNA strands run antiparallel?
It allows the nitrogenous base strands to come in contact near the center of the molecule
it allows them to carry a sequence of nucelotides
Parts of DNA
sugar and phosphate backbone
nitrogeneous bases- nucleotides - CGTA
deoxyribose
Is DNA a molecule or its own thing?
DNA is a molecule
How does replication happen?
2 Strands seperate
new complementary strands synthesize
Can DNA strands pair randomly?
No, each strand of DNA is a template for the next
The S part of the cell cycle
enzymes break apart hydrogen bonds and unwind the DNA
DNA polymerase proofread and connect a new matching strand of DNA
DNA replicates
all must finish before mitosis or meiosis
What enzyme is involved in all types of DNA replication?
DNA polymerase
what are the building blocks of nucleic acids
nucleotide
what is meiosis
cell division with 4 daughter cells
what is mitosis
cell division with 2 daughter cells
what do polymearse do?
proofread DNA and join nucleotides together to make complementary DNA
what happens if a cell divides before DNA replication
lack of DNA can lead to bad genetics or death of the cell
replication in prokaryotic cells
regulatory proteins cling to chromosome in cytoplasm starting S cycle
proceeds in 2 directions until chromosome is copied
chromosomes attach to different parts of membrane and split when daughter cell forms
replication in eukaryotic cells
regulatory proteins cling to chromosome in nucleus starting S cycle
starts in many places until copied and proofread separately
