Nucleic Acids & Fertility Rates (Human Body Science) Flashcards
Fertility Rates
Fertility rates refer to the average number of children women will have during their childbearing years, which are between the ages of 15 and 44.
What is significant about fertility rates?
Fertility rates are significant because they coincide with the replacement rate; which is the number of births needed to maintain the population at its current number.
Crude Birth Rate
Defined by the number of births per 1,000 people per year
Crude Death Rate
Defined by the number of deaths per 1,000 people per year.
Nucleic Acids
Primarily DNA and RNA; the job of nucleic acids is to store and transmit hereditary information.
Structure of Nucleic Acids
Structurally, a nucleic acid is a chain of nucleotides that consist of:
- pentose -phosphate group and- nitrogenous base.
Pentose of Nucleotide
A pentose is a type of sugar.
Phosphate group of Nucleotide
A molecule in the backbone of DNA and RNA that link adjoining bases together.
Nitrogenous Bases of Nucleotide
A nitrogenous base is a molecule found in DNA and RNA that encodes genetic information in cells.
What are the 5 types of Nitrogenous Bases?
Adenine, Cytosine, Guanine, Thymine, Uracil
Which nitrogenous base is only found in RNA?
Uracil
How do bases match up in DNA?
Adenine (A) – Thymine (T)
Guanine (G) – Cytosine (C)
Purines
Purines make up 2 of the 4 nitrogenous bases in DNA and RNA and have two carbon rings.
Purines = Adenine & Guanine (A&G)
Pyrimidines
Pyramidines only have one carbon ring. Pyramidines= cytosine, thymine, and uracil
Differences between RNA and DNA
DNA:
•In DNA, the pentose sugar is Deoxyribose
•The nitrogenous bases found in DNA are adenine, guanine, thymine, and cytosine.
•A – T / G – C
•DNA has a double-helix structure
•Contains hydrogen, oxygen, nitrogen, phosphorus
RNA:
•In RNA, the pentose sugar is ribose
•The nitrogenous bases found in RNA are adenine, guanine, uracil, and cytosine.
•A – U / G – C
•RNA has a single strand of nucleotide
•Contains hydrogen, oxygen, nitrogen, phosphorus
What is the function of RNA?
RNA acts as the messenger and decoder for DNA in order to synthesize proteins and does so by using three forms:
Messenger RNA / Ribosomal RNA / Transfer RNA
What are the steps from DNA to RNA to Protein Synthesis:
DNA⇒ Transcription ⇒ Translation ⇒ Protein Synthesis
Messenger RNA (mRNA)
It is a relatively long strand of nucleotides that look like “half DNA” molecules. mRNA carries a transcript of the code to the cytoplasm, where protein synthesis occurs.
Ribosomal RNA (rRNA)
Ribosomal RNA (rRNA) rRNA is ribosomes that are made up of two subunits – one small and one large. They combine to make a functional ribosome along with protein that are literally the sites of protein synthesis.
Transfer RNA (tRNA)
Ferry amino acids to ribosomes where they decode mRNA’s message for amino acid sequence in the polypeptide to be built.
Transcription
The process in which DNA’s information is encoded into mRNA.
Translation
The process after transcription in which the information carried by mRNA is decoded and used to make polypeptides (protein)
Genetic Code
The rules by which a base sequence of a gene is translated into an amino acid sequence.
Codon
For every three-base sequence of DNA there is a corresponding three-base sequence of mRNA which is what makes up a codon.
Anticodon
The anticodon is the result of the corresponding part of the mRNA three base sequence, it is the head of tRNA.
What is so significant about tRNA?
tRNA is the link between the language of nucleic acids and the language of proteins
What happens one tRNA’s anticodon is loaded with it’s correspoinding amino acid base?
It carries that information to the ribosomes. The ribosome has one binding site for mRNA and three for tRNA.
Where does transcription occur?
Nucleus
Where does translation occur?
Cytoplasm
What is the starting amino acid for translation coding called?
Methionine
Introns vs. Exons in transcription
Introns are sequences that are removed after transcription.
Extrons are kept after transcription.
