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Danna Esther Gelfand
Jed Quiaoit
Danna Esther Gelfand
Jed Quiaoit
Nucleic acids are large complex molecules that play a crucial role in the storage, transmission, and expression of hereditary information. They are made up of monomers called nucleotides, which consist of a 5-carbon sugar, a nitrogenous base, and a phosphate group.
There are two main types of nucleic acids: deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). DNA is the genetic material that stores the instructions for building proteins, while RNA is involved in the synthesis of proteins from the instructions stored in DNA. 🍭 Genes are a specific unit of inheritance that contain the instructions for synthesizing particular proteins. They are made of DNA and are found on chromosomes. The sequence of nucleotides in a gene determines the sequence of amino acids in a particular protein, which in turn determines the protein's function. 🔧
Deoxyribonucleic acid (DNA) is a molecule that stores and transmits genetic information. It is responsible for directing its own replication, causing the synthesis of messenger RNA (mRNA), and using mRNA to control protein synthesis. The sugar in DNA is deoxyribose.
Nucleic acids have a linear sequence of nucleotides that are linked by covalent bonds. The sequence is defined by the presence of a hydroxyl group (-OH) on the 3' carbon of one nucleotide and a phosphate group on the 5' carbon of the next nucleotide. During DNA and RNA synthesis, nucleotides are added to the 3' end of the growing strand, forming covalent bonds between adjacent nucleotides. This process is essential for the replication and expression of genetic information. 🧠
Uracil is only found in RNA, while thymine is only found in DNA. The nitrogenous bases can be divided into two categories: purines and pyrimidines.
A prime (ʹ) identifies the carbon atoms in the ribose, such as the 2ʹ carbon or 5ʹ carbon. DNA is structured as an antiparallel double helix, with each strand running in opposite 5’ to 3’ orientation, and the 5’ end of one molecule is paired with the 3’ end of the other molecule and vice versa.
A researcher isolates a sample of DNA from a species of plant and finds that it contains the following amounts of the four nitrogenous bases: adenine (A) = 40%, thymine (T) = 40%, and cytosine (C) = 10%.
According to Chargaff's rule, what is the percentage of guanine in the sample?
To solve this problem, we can use Chargaff's rule, which states that in a double-stranded DNA molecule, the percentage of A is equal to the percentage of T, and the percentage of G is equal to the percentage of C.
Since the percentage of A in the sample is 40% and the percentage of T is 20%, we know that the percentage of G must be equal to the percentage of C, which is 10%. Therefore, the percentage of guanine in the sample is 10%!
While it's highly unlikely for an AP Biology standalone MCQ or FRQ to ask about the similarities and differences between DNA and RNA, it's important to learn the foundational knowledge to answer more complex, application-centered questions down the road!
⭐ Key similarities between the two:
⭐ Key differences between the two:
Check out the AP Bio Unit 1 Replays or watch the 2021 Unit 1 Cram
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