CHAPTER 5 Flashcards
Genetics
study of inheritable traits as expressed in an organism’s genetic material
Genome
the entire genetic complement of an organism, includes its genes and nucleotide sequence.
DNA Structure: Antiparallel
two complimentary strands of DNA form a double helix with each strand being parallel to each other but oriented in the opposite direction.
RNA Structure: messenger RNA (mRNA)
contains the code to make polypeptides
transfer RNA (tRNA)
attaches amino acids and brings them to ribosome during translation
ribosomal RNA (rRNA)
helps form the ribosome and peptidyl transferase
small Nuclear RNA (snRNA)
helps with splicing of eukaryotic mRNA during process
regulatory RNA; antisense RNA (asRNA)
can bind to mRNA and prevent them from being translated
micro-RNA (miRNA)
can bind to mRNA molecules to prevent them from being translated by recruiting enzymes that hydrolyze them
small Interfering RNA (siRNA)
See miRNA
Haploid
single chromosome copy
The study of genes and how their expression produces traits in an organism and how they are inherited from one generation to the next is called?
genetics
The entire genetic compliment of an organism (i.e., all the DNA found in an organism) is called
genome
Nucleotides consist of what three components?
- Phosphate
- Pentose sugar
- Nitrogenous base
Which two of the three components above contribute to the identity of nucleic acids?
Pentose sugar and nitrogenous base
What are the five different nitrogenous bases for nucleotides?
Adenine (A), Thymine (T), Guanine (G), Cytosine (C), Uracil (U)
What are four major differences between DNA and RNA?
DNA – contains deoxyribose sugar, double stranded, stable under alkaline conditions
RNA - ribose sugar, single stranded, not stable under alkaline conditions
They each perform different functions in the human body
The two complimentary strands of DNA form a double helix with each strand being parallel to each other but oriented in the opposite direction. What is the term that describes this orientation?
antiparallel
Add the complementary DNA nucleotides to the sequence of DNA
nucleotides shown below. Be sure to include the directionality of the
complimentary strand.
5’ GCTACGTAATCGGTACGT 3’
3’ CGATGCATTAGCCATGCA 5’
What is the function of DNA?
Stores the genetic material of an organisms in special regions called genes
What allows RNA to have many functional forms?
It can take many forms because it is single stranded
What are the five main types of RNA and their basic shape and function?
Which three types of RNA are directly involved in the process of translation for all cells?
Add the complementary RNA nucleotides to the sequence of DNA nucleotides shown below. Be sure to include the directionality of the complimentary strand.
5’ GCTACGTAATCGGTACGT 3’
Answer the questions comparing bacterial and eukaryotic genomes
Circular or linear chromosomes?
Single or multiple chromosomes per cell?
Haploid or diploid?
Location of chromosomes in cell? Possess plasmids?
BACTERIAL
Circular Single
Haploid
Nucleoid of cytoplasm and in plasmids
Yes, in some cells
EUKARYOTE
Linear Multiple
Diploid
Nucleus in mitochondria chloroplast and plasmids in cytosol
In some fungi, algae, and protozoa
What are the four main types of bacterial plasmids and what type of genes they contain?
- Fertility plasmids – sex pilius- allow for conjugation
- Resistance plasmids – resistance for antibiotics
- Bacteriocins plasmids – kill other bacteria
- Virulence plasmids – increase pathogens
Why do cells need to replicate their genomes?
To prepare for the cell to divide
The process by which all chromosomes of a cell are copied identically just before the cell divides is called
DNA replication
Is the process of DNA replication catabolic or anabolic?
Anabolic
Is the process of DNA replication exactly the same in eukaryotes as it is in bacteria or is it somewhat different?
Different
DNA replication is considered a “semi-conservative process”. What does the term semi-conservative mean?
The daughter DNA molecules consist of one original strand and one new strand
What are the four main requirements for DNA replication to occur?
- Double stranded parental DNA with origin of replication
- Enzymes
- Stabilizing proteins
- Deoxyribonucleotides triphosphates (dNTPs)
- RNA primer
Does extrachromosomal DNA (plasmid DNA) also undergo DNA replication? If so, does it replicated the same time as the chromosome or at different times?
Yes, it undergoes replication but independently
Parental DNA contain a special region or regions where the process of DNA replication begins. What are these regions called?
Origin of replication
What do deoxyribonucleoside triphosphates (dNTPs) consist of?
Deoxyribose, one of the four DNA nitrogenous bases, and three phosphates
dNTPs serve what two purposes during DNA replication?
They provide the nucleotide (monophosphate nucleotide) and are a source of high energy
What are the four dNTPs used during DNA replication?
dATP, dTTP, dGTP, dCTP
What are the five main enzymes needed for DNA replication and their function?
- Topoisomerase (jyrase) – relives supercoiled DNA tension ahead of the replication fork so that DNA helicase can progress
- DNA helicase – separates double stranded DNA by breaking the hydrogen bonds between complementary base pairs
- Primase – creates the primer
- DNA polymerase
What role do single stranded binding proteins play during DNA replication?
Binds to each separate DNA molecule to prevent the two strnds from coming back together so that each can act as a template
What are the three points of interest that are different than eukaryotic DNA replication:
- Bacteria has 1 origin of replication
- It only uses twi DNS polymerase (I &III). The DNA polymerase that adds al the new DNA nucleotides that form the new complimentary strand is DNA polymerase III and the one that the RNA primers with DNA nucleotides is DNA polymerase I.
- Bacteria DNA replication uses a specific topoisomerase called DNA gyrase
DNA replication can be summarized into what three general steps? What happens during each step?
- Initiation – involves the separation of the double stranded DNA by DNA helicase and the formation of the replication bubble.
- Elongation – Involves the uniting of the two replication forks and the replacement of the RNA primers with DNA nucleotides.
- Termination – involves the polymerization of DNA by the DNA polymerase enzyme
Use the space below to replicate the following double stranded molecule of DNA. Make sure you synthesize each new daughter strand at the correct starting end just like DNA polymerase does in cells.
5’ AATAGGTATTCGGTGCGA3’
3’ TTATCCATAAGCCACGCT 5’