Module 5 Flashcards
The ______ is bounded by a double membrane and contains the materials needed to control all parts of the cell.
nucleus
The genetic material - ________ and 3 forms of ________ - are all made in the nucleus.
deoxuribonucleic acid (DNA) and ribonucleic acid (RNA)
What are the functions of the nucleus?
- Storage of the cell’s genetic material
- Synthesis of the protein coding material
The _____ is a ribosome factory.
nucleolus
DNA can be used to make a copy of itself. This process is called __________.
replication
The process by which DNA makes RNA is called _______. The basic structure of DNA and RNA are the same so this refers to copying from on form to another in the same language.
transcription
RNA to protein is called ________. This process is a converting from one “language” to another.
translation
____ makes _____ makes _____.
DNA - RNA - protein
Some viruses use RNA as their genetic material. These carry the code for an enzyme called _________ that converts RNA to DNA.
reverse transcriptase
_______ uses RNA as a template to make DNA. After that step, the usual sequence (DNA - RNA - protein) is followed.
Reverse transcriptase
DNA is visible through the light microscope only when it is packaged into ______ during cell division.
chromosomes
______: unspooled, “loose” DNA strands.
chromatin
The DNA molecule is a double helix; the two strands are _____, which means that one goes up while the other goes down.
antiparallel
We define up and down on the DNA molecule by the numbering of carbons on the sugar part of the backbone. The _____ is where we start reading, and where the enzymes that work on the DNA start their work. The ______ is where everything ends up.
5’ carbon;
3’ end
_____ is the most stable of molecules, almost as stable as a rock.
DNA
_____ exists just long enough to make proteins, then it is destroyed.
RNA
________ is very unstable. It allows for transcriptional control of protein production. It carries the coded message.
Messenger RNA (mRNA)
_______ is more stable. With proteins, it forms ribosomes; small and large subunits.
RIbosomal RNA (rRNA)
______ is more stable. It is the “truck” to bring amino acids to the growing protein strand.
Transfer RNA (tRNA)
The rRNA components of the ribosome are (mostly) made in a structure within the nucleus called a _______.
nucleolus
In the cytoplasm, rRNA and proteins are assembled into the _______.
ribosome
Ribosomes exist as either ________ or as part of the ________. Either way, they operate as translation factories.
free ribosomes;
rough endoplasmic reticulum (RER)
_____ complexes with proteins to form the ribosome.
rRNA
On the ribosome, the _____ message is read and the proteins are assembled.
mRNA
_____ molecules carry the amino acids to the ribosome to be incorporated into proteins.
tRNA
A _____ is a segment of DNA that codes for a protein.
gene
The final edited version of the RNA made from the DNA template is called ______ because it carries the message (instructions for making proteins).
messenger RNA (mRNA)
Messenger RNA leaves the nucleus through _____ to the cytoplasm, where the protein factories - ribosomes - read the mRNA message and translates it to a particular sequence of amino acids in the growing protein (primary structure).
nuclear pores
The process of RNA synthesis begins as the DNA double helix is opened up. Only one DNA strand is read. It is called the ______, since is carried the genetic code.
coding strand
_____ is the expressed region of DNA (made into proteins).
Exon
_____ is the intervening region of DNA (not made into proteins).
Intron
The ______ is the portion of the DNA that is expressed, or made into protein.
exon
The _____ is the portion of the DNA that is not made into protein and must be edited out.
Intron
In order to create mRNA, the introns must be sliced out and the exons stitched together, This is accomplished by an organelle called the _______, which is made up of several small nuclear ribonucleoprotein pareticles, or snRNP.
spliceosome
A structure called a ____ is formed, the intron is cut out, and the ends of the exon are stitched together.
lariat
Mutations, as you might expect, can mess up the process of splicing. This has been shown for the blood disorder called ________.
Beta thalassemia
_______ is a protein that makes up half of hemoglobin, the oxygen carrying protein of red blood cells.
Beta-globin
Abnormal splicing of the _______ gene produces an abnormally short globin mRNA.
beta globin
RNA is ____ into protein.
translated
______ changes nucleic acid “language” (mRNA) to amino acid “language” (protein).
Translation
The _____ polymer is a coded message containing the adenine (A), cytosine (C), guanine (G), and uracil (U).
mRNA
The ____ polymer is the product of translation: 20 different types of amino acids strung together in a specific order make up the protein’s primary structure.
protein
Protein synthesis occurs through the action of a macromolecule machine called a _______.
ribosome
______ make proteins that the cell needs.
Free ribosomes
The _____, ____, and _______ together make proteins for export, to be embedded in the cell membrane, or to recycle proteins that are malformed.
ribosomes, RER, and Golgi
______ are usually, but not always, found on the cell surface.
Glycoproteins
________ carries the coded message from the nucleus to the ribosome.
Messenger RNA
The ribosome is made up of _____ and ______.
ribosomal RNA and proteins
Each tRNA has a unique _____ (a set of 3 ribonucleotides which will bind to the mRNA).
anticodon
The anticodon is paired with a specific amino acids which binds to an _______.
acceptor arm
What are the steps for translation?
- Ribosome attaches to mRNA.
- AUG start codon matched up to tRNA - methionine.
- Next tRNA-amino acid arrives.
- Peptide bond forms.
- Ribosome shifts 3 mRNA bases.
- Polypeptide chain grows.
- Ribosome reaches stop codon; polypeptide released
Three base pairings on mRNA coding for an amino acid are called a ______.
codon
Transfer RNAs contain an ______ at one end of the molecule that lines up with and complements the mRNA codon.
anticodon
The 3 base sequence representing each amino acid is called the _______.
genetic code
Because there are 64 combinations of bases for 20 amino acids, the genetic code is called _______, meaning there are more possible codes than there are amino acids to encode.
degenerate
Protein synthesis ends with either _____, ______, or ______. These are called stop codons.
UAA, UAG, UGA
UAA is called _____.
ochre
UGA is called ______.
umber
UAG is called _____.
amber
A _____ is a change in the sequence of DNA which changes the mRNA made from the coding strand.
.gene polymorphism
If the change in the DNA (and mRNA) results in a change in the amino acid sequence, which then changes the function if the resulting protein, then the change is called a ______.
mutation
If we introduce a mutation after the start codon, that either adds or subtracts a base, the entire frame is shifted so that all amino acids downstream from the mutation are wrong. This is called a _________.
frameshift mutation
Frameshift mutations are not the only kind. Sometimes a single base is changed, which does not shift the reading frame. This is called a ________.
point mutation
The mutation that produces the disease, sickle-cell anemia is a ________.
point mutation
After replicating their DNA in preparation for cell division, chromosomes consist of two identical ______.
chromatids
Each _____ is a single, continuous DNA molecule.
chromatid
______: two identical halves of the chromosome, joined at the centromere.
Chromatid
______: DNA strand.
Chromatin
_______: visible packaging of DNA and histones into X-shaped structures.
Chromasomes
______ carry a lot of positive charges to screen of negative energy that DNA gives off.
Histones
Cells which are dividing go through a series of steps that is called the _______.
cell cycle
The actual process of cell division is called _____ or ______.
mitosis or M phase
After mitosis, a dividing cell enters a _____ called G1. G1 takes 8-10 hours to complete.
first growth phase
If a cell becomes _______ (i.e. is in a resting state), or if it is incapable of cell division, it is “parked” in a part of the cell cycle called G0.
quiescent
During the S phase, the cell’s DNA is _____ so that it can be divided equally between the daughter cells in mitosis. This process takes about 8 hours.
replicated
After S phase, cells enter the _____ or ______ called G2. During G2, the cell finalizes its preparations for mitosis. After 4-6 hours of G2, the cell enters M phase, which completes the cycle.
second growth or gap phase
________, the copying of all the cell’s DNA molecules, occurs during the S phase of the cell cycle.
DNA replication
The 2 strands of the DNA double helix are ______.
anti-parallel
As DNA is replicated, 2 different strategies are used:
- leading strand built continuously 5’ —> 3’
2. lagging strand uses Okazaki frangments to build short segments which are then stitched together.
____ is the term for all parts of the cell cycle except mitosis: G0, G1, S, and G2.
Interphase
During interphase, the DNA is loosely packed so that it may be transcribed to RNA as needed. In this form, it is called ______.
chromatin
Mitosis has 4 parts: ____, _____, _____, and ______.
prophase, metaphase, anaphase, and telophase
In the last step in mitosis, the cells must physically divide into 2 daughter cells. This physical division is called ________.
cytokinesis
While all parts of interphase involve preparation for, or recovery from, mitosis, the first phase of mitosis that involves an obvious, observable visual change in the cell is ______.
prophase
The ______, which grows out of the chromosome is made up of the microtubules used to move chromosomes.
mitotic spindle
_____, as the name implies, is the middle phase of mitosis, in which everything in the parent cell lines up in the middle.
Metaphase
Metaphase is the stage of mitosis used to create a _____, a picture of the chromosomes that is used (for example) to diagnose disorders with a change in the number of chromosomes. Trisomy 21, or Down syndrome is an exmaple.
karyotype
_____ is the stage of mitosis where the contents of the 2 daughter cells move backwards, away from each other.
anaphase
During _____, mitosis is completed.
telophase
A _____ appears in the middle of the parent cell, and as the furrow deepens, the cell is split into 2 daughter cells.
cleavage furrow
The daughter cells move apart in a process called ______.
cytokinesis
______ are those that can make new little humans.
Germ cells
To evenly divide up the replicated amount of DNA between gametes, a slightly different mechanism of cell division is needed. This is called ______.
meiosis
One major advantage to sex is that it provides the opportunity for _____ during meiosis. This scrambles the genetic material so that each sibling, even in a large family, has a different complement of DNA.
crossing over
_____ creates 2 daughter cells that are identical to the “parent”.
Mitosis
______ halves the DNA content in Meiosis I and then Meiosis II resembles mitosis.
Meiosis
In Mendelian terminology, the variations of these genes are called ______.
alleles
_______ are those where inheriting one copy (from mom or dad) will give you a condition or disease.
Dominant alleles
______ are those where inheriting one copy makes you a carrier, and inheriting 2 copies will give you a condition or disesase.
Recessive alleles
_______ are used to analyze Mendelian genetics.
Punnett squares
