DNA Mutations + Sickle Cell Flashcards
What are the three gene point mutations?
Substitution, insertion, and deletion
What gene point mutation is associated with sickle cell anemia?
Substitution
What is substitution/Missense mutation?
One base is incorrectly added during replication and replaces the pair in the corresponding position on the complementary strand
What is deletion?
One or more nucleotides is “skipped” during replication or otherwise excised, often resulting in a frameshift
What is insertion?
One or more extra nucleotides are inserted into replicating DNA, often resulting in a frameshift
What does a “sickle-cell” red blood cell look like?
It’s crescent shaped (or sickle shaped) and it forms clots and blockages.
What happens to the hemoglobin when someone has sickle cell anemia?
The hemoglobin clumps up and forms long rods instead of healthy, round red blood cells.
What is the hemoglobin?
The proteins in the blood
What are the nucleotides in a DNA strand?
they are the letters (ex. C from the codon CCT)
What is a codon?
A sequence of three consecutive nucleotides in DNA or RNA
Where is DNA located?
In the nucleus
Where are codons located?
Codons are present on the mRNA and DNA strands
What are all of the types of RNA?
Messenger RNA (mRNA), ribosomal RNA (rRNA), and transfer RNA (tRNA).
What is the process called when DNA is translated to mRNA?
Transcription
What is the process called for when mRNA is translated to amino acid (or polypeptide)?
Translation
Where are the ribosomes located and what happens to the mRNA strands there?
Ribosomes are located at the cytoplasm and it is where translation occurs after have transcribed the DNA.
What is the enzyme that is used during transcription?
RNA polymerase
What enzyme separates (or “unzips”) the two strands of the DNA double helix?
DNA helicase
What enzyme makes mRNA from DNA?
RNA polymerase
What does a DNA polymerase do?
Adds nucleotides one by one to the DNA chain
What does DNA stand for?
Deoxyribonucleic Acid
What is RNA?
RNA stands for Ribonucleic acid and is a short and single stranded molecule
What is the sugar in DNA?
Deoxyribose
What enzyme is used during translation?
Ribosomes are used during translation
What is a mutation that changes a nucleotide but does not change the amino acid?
A Silent mutation
Which enzyme connects pieces of the lagging strand
Ligase
The process by which cells make proteins
Protein synthesis
The building block of proteins.
Amino acids
The nitrogenous base that is found only in RNA.
Uracil (U)
What is mRNA produced by?
By transcription
What does tRNA carry?
carries amino acids to ribosome
Gene
Section of DNA that codes for a protein → traits
Protein
made from a sequence of amino acids (aka polypeptide)
DNA
long, double-stranded molecule that stores all of an organism’s protein instructions
Mutation
any change in the DNA code; may be positive, neutral or negative depending on how it impacts the structure of the protein
Point Mutation
single nucleotide change (substitution=swap)
Nondisjunction
process by which chromosomes do not separate properly during meiosis (having one extra or one less chromosome).
Autosomes
referring to first 22 pairs of chromosomes, does not include sex chromosomes
Co-dominant and Incomplete Dominance
A heterozygous inheritance that results in a new, mixed phenotype different from either parent. Codominace (red + white = red and white) and Incomplete Dominance (red + white = pink).
Meiosis
The process by which haploid gametes are formed
Mitosis
The process by which two diploid somatic cells are produced for growth and repair
46
The number of chromosomes in a human body cell
23
The number of chromosomes in a human gamete cell
Diploid
Two copies of each chromosome
Haploid
One copy of each chromosome (half the normal chromosome #)
(Law of) Segregation of Alleles
The random sorting and pairing of chromosomes during Meiosis
A, B, O
The multiple alleles which control blood type in humans
Gamete
Haploid sex cell
Crossing-Over
When segments of DNA are exchanged between chromosomes during Meiosis
Fertilization
Process by which haploid gametes combine to form a diploid zygote
Frameshift Mutation
one or more nucleotides are deleted or inserted into a gene, lengthening or shortening the entire sequence
Chromosomes
supercoiled, condensed DNA
Independent Assortment
the alleles of two (or more) different genes get sorted into gametes independently of one another.
