TEAS 7 - Science (Genetic Material and Proteins) Flashcards
___, or deoxyribonucleic acid, is a molecule that contains the genetic instructions for the development and functioning of all living organisms.
DNA
DNA is often referred to as the “___ ___ of life” because it carries the information that determines the characteristics and traits of an individual.
building block
DNA is found in the nucleus of cells and is made up of smaller units called ___.
nucleotides
What does each nucleotide consist of?
sugar molecule, phosphate group, and a nitrogenous base
What are the four types of nitrogenous bases in DNA?
Adenine (A)
Thymine (T)
Cytosine (C)
Guanine (G)
Adenine bonds with ___ while Guanine bonds with ___.
Thymine
Cytosine
Adenine always bonds with Thymine and is held together with ___ ___ bonds. Guanine always bonds with Cytosine and is held together by ___ ___ bonds.
two hydrogen
three hydrogen
Can adenine bind with cytosine? Can guanine bind with thymine?
No and No
*Adenine cannot bond with cytosine because adenine does not have a third place in its structure for another hydrogen bond.
The ___ and arrangement of these bases along the DNA molecule create a specific genetic code
order
So how does our DNA end up in each of our cells in order to code for proteins?
organisms grow and develop through the process of cell division; before cell division takes place, DNA must replicate to ensure that each new cell receives an exact copy of the genetic information
What are mutations?
changes in DNA
___, or changes in the DNA, can happen spontaneously or due to external factors like radiation or certain chemicals. Some mutations can have no significant effect on our cells, while others can cause genetic ___.
Mutations
disorders
Each gene is a specific segment of ___ that only codes for ___ specific protein.
DNA
one
How many proteins does one gene code for?
one protein
What is the relationship between genes, DNA, and proteins?
One gene = One segment of DNA = One protein coded
We all have ___ copies of each gene in our DNA. We get one copy from our biological ___ and one copy from our biological ___.
two
mother
father
Chromosomes are thread-like structures found in the nuclei of cells. They are made up of ___, along with ___ that help organize and support the DNA.
DNA
proteins
How many chromosomes do humans have? How many pairs do they have?
46 chromosomes
23 pairs
Each chromosome contains numerous segments of DNA called ___.
genes
Genes are specific stretches of DNA that carry instructions for creating ___, which are essential for various biological functions.
proteins
Chromosomes also play a role in genetic disorders, caused by abnormalities or ___ in specific genes located on chromosomes.
These mutations can lead to a ___ in protein production or function, resulting in various health conditions or inherited diseases.
mutations
disruption
Review the relationship between the three levels of genetic material. List them from the smallest to the largest component (chromosomes, DNA, genes).
DNA → Genes → Chromosomes
Visualize this: Think of ___as a long string, like a necklace made up of different beads. The beads represent ___, which are specific segments of DNA. Now imagine that you take that necklace and wind it around small balls. Those balls represent ___ (called histones), and when the DNA is wrapped around the proteins, it forms the structure of a ___.
DNA
genes
proteins
chromosome
Which of the hereditary units is responsible for carrying genetic information from parents to offspring?
DNA
Which of these is responsible for determining the sex of an individual?
Chromosomes
Which of these statements best reflects the role of genes?
Genes code for enzymatic proteins, non-enzymatic proteins, and RNA.
Which of these units code for a protein?
Gene
Which of these statements correctly describes the relationship between a gene and a chromosome?
Chromosomes are made up of genes.
Which of the following is the most accurate description of the link between chromosomes and DNA?
Chromosomes include numerous genes, each of which is made up of a DNA sequence.
Each protein is coded for by a _____.
Gene
The double-helical structure of DNA consists of __________.
a sugar molecule, a phosphate group, and nitrogen bases
The two strands of the DNA are __________.
anti-parallel
Which of these bonds would we see between nitrogenous bases?
Hydrogen bonds
Why does guanine show base-pairing only with cytosine?
For stabilization, by forming three hydrogen bonds
How many nucleotides are present in a codon?
3
What are the two main types of nucleic acids?
DNA
RNA
What does RNA stand for?
ribonucleic acid
While DNA is ___-stranded, RNA is ___-stranded.
double-stranded
single-stranded
Are DNA and RNA the same?
No, they have key differences and have different roles
Another key difference is that RNA has ___ as the sugar in the structure, whereas DNA has ___ (that’s why their names are different!).
ribose
deoxyribose
___ is a double-stranded molecule, where the two halves are “zipped” together. ___, on the other hand, is usually a single strand of nucleotides.
DNA
RNA
What is the name of the sugar in RNA?
ribose
What is the name of the sugar in DNA?
deoxyribose
Are the nitrogenous bases in DNA and RNA the same?
No
What are the nitrogenous bases in DNA?
Adenine, Thymine, Guanine, and Cytosine
What are the nitrogenous bases in RNA?
Adenine, Uracil, Guanine, and Cytosine
How do the functions of DNA and RNA differ?
DNA carries genetic information (storage)
RNA transfers genetic information (transport)
DNA ___ genetic information (storage) while RNA ___ genetic information (transport).
carries
transfers
How do the nitrogenous bases in DNA and RNA differ?
DNA has adenine (A) which pairs with thymine (T) and guanine (G) which pairs with cytosine (C)
RNA has adenine (A) which pairs with uracil (U) and guanine (G) which pairs with cytosine (C)
*RNA uses uracil (U)
___ carries genetic information from DNA to the ribosomes. It acts as a template or a “messenger” by transcribing the DNA code and bringing it to the ribosomes, where protein synthesis occurs.
mRNA
What are the different types of RNA?
mRNA
tRNA
rRNA
mRNA stands for ___ RNA, tRNA stands for ___ RNA, and rRNA stands for ___ RNA.
messenger RNA
transfer RNA
ribosomal RNA
mRNA carries genetic information from ___ to the ribosomes. It acts as a template or a “messenger” by ___ the DNA code and bringing it to the ribosomes, where protein synthesis occurs.
DNA
transcribing
tRNA helps in the translation process by bringing ___ ___ (the building blocks of proteins) to the ribosomes. Each tRNA molecule is ___ to a particular amino acid, and it ensures that the correct amino acids are brought to the ___ according to the mRNA instructions.
amino acids
specific
ribosomes
___ helps in the translation process by bringing amino acids (the building blocks of proteins) to the ribosomes.
tRNA
___ is a vital component of ribosomes, the cellular structures where proteins are assembled.
rRNA
rRNA is a vital component of ___, the cellular structures where proteins are ___. Ribosomes consist of rRNA and proteins, and they provide the necessary framework for protein synthesis to occur.
ribosomes
assembled
What do ribosomes consist of?
rRNA and proteins
What is the central dogma of molecular biology?
it describes how genetic information flows from DNA to RNA to proteins
___ is the process of your cell making a copy of your DNA using mRNA.
Transcription
What are the 2 processes that need to take place in order to create proteins?
transcription
translation
___ is the process of the ribosome using that strand of mRNA to create a new protein.
Translation
What is a memory trick for the word and process of transcription?
When we transcribe something, we’re writing it down – basically, we’re making a copy. When our DNA is transcribed, a copy is made using mRNA.
What is a memory trick for the word and process of translation?
When something is translated, it is taken from one language and put into another. This is essentially what happens in this step of protein synthesis. The RNA and ribosomes take the language of the mRNA and translate it into amino acids in order to make a protein.
Where does transcription take place?
the nucleus
(that’s where the DNA is!)
At the beginning of transcription, the DNA molecule ___ and unzips, exposing a specific gene that creates a specific protein that the cell needs.
unwinds
What is the name of the enzyme that binds to the gene and starts “reading” the DNA sequence?
RNA polymerase
As the RNA polymerase moves along the DNA strand, it creates a single-stranded molecule called ___ ___ (mRNA).
messenger RNA
The mRNA molecule is ___ to the DNA template strand.
complementary
When the RNA polymerase sees cytosine (C), it adds a ___ to the strand of mRNA (and vice versa).
guanine (G)
When RNA polymerase sees thymine (T), it adds ___. Finally, the only difference in base pairing during transcription occurs when RNA polymerase reads adenine (A) on the DNA strand. In that case, it adds a ___ to the new strand, not a thymine (T).
adenine (A)
uracil (U)
Once the mRNA molecule is complete, it ___ from the DNA template and leaves the nucleus, carrying the genetic instructions to the next step which is ___.
detaches
translation
Where does translation occur?
in the cytoplasm
(where the ribosomes are)
At the end of transcription, the mRNA molecule leaves the ___ and attaches itself to a ___ in the cytoplasm. This is the beginning of translation.
nucleus
ribosome
How many bases does the read on the mRNA sequence at a time?
3
The ribosome reads the mRNA sequence ___ bases at a time. Each set of 3 bases is known as a ___.
3
codon
What does each codon code for?
a specific amino acid
Each codon codes for a specific ___ ___. There are also specific codons known as “___” and “___” codons. These codons tell the cell machinery where the beginning and the end of the amino acid chain are for that specific protein.
amino acid
“start”
“stop”
___ molecules are specialized RNA molecules that bind both to specific amino acids and specific codons on the mRNA.
tRNA
So, how do we go from “reading” the mRNA to the creation of a protein?
Transfer RNA (tRNA)
The unique structure of the tRNA allows it to bind to and carry a specific ___ ___, while also having a specific “___” that allows it to bind to the corresponding codon on the mRNA. Then it transfers the amino acid to the new peptide chain.
amino acid
“anticodon”
As the ribosome moves along the mRNA strand, it joins the amino acids carried by the ___ molecules together in a specific order dictated by the mRNA sequence.
This process continues until the ribosome reaches a “___” codon on the mRNA, signaling the end of protein synthesis.
The newly synthesized protein is then ___ from the ribosome and can go on to perform its specific function in the cell.
tRNA
stop
released
What are “start” and “stop” codons?
they are specific codons that never change and they signal to the ribosomes where to START and STOP creating a protein
What is the sequence for the “start” codon?
AUG
Whenever AUG is read, the ribosome knows that it’s time to ___ building a protein.
start
When the ribosome reads UAG, UAA, and UGA, it knows that it has reached the ___ of the amino acid chain.
end
What are the sequences for the “stop” codons?
UAG
UAA
UGA
What is a memory trick for the “start” codon?
Start codon: AUG
“School STARTS in AUGust”
What is a memory trick for the “stop” codons?
Stop codons: UGA, UAA, and UAG
UAA: “U Are Annoying!”
UGA: “U Go Away!”
UAG: “U Are Gone!”
Which nitrogenous base is seen in RNA but not in DNA?
Uracil (U)
A ___ is a sequence of 3 nucleotides on a messenger RNA that codes for a specific amino acid.
codon
Which RNA carries genetic information from the nucleus to the cytoplasm?
Messenger RNA
___ carries amino acids to the ribosome for assembly.
Transfer RNA (tRNA)
Which of the following correctly describes the function of the ribosomal RNA?
It catalyzes the formation of bonds between the amino acid molecules
Which bond is present between base pairs of RNA?
Hydrogen bond
Which organelle is responsible for protein synthesis?
Ribosomes
How many subunits are present in a ribosome?
2
What happens to DNA during transcription?
DNA unwinds
Which enzyme helps DNA unwind?
Helicase
What is formed at the end of transcription?
Messenger RNA (mRNA)
Which enzyme helps to initiate transcription?
RNA polymerase
What is the process of using messenger RNA to create proteins?
translation
What enzyme reads the DNA sequence and synthesizes a complementary strand of mRNA?
RNA polymerase enzyme
Where is transfer RNA primarily located?
cytoplasm
What serves as the template for making proteins during translation in cells?
Messenger RNA (mRNA)
