HESI Science Portion (Biology): Nucleic Acid and Protein Synthesis

What do chromosomes consist?

Genes

Are single units of genetic information

What are genes made up of?

Deoxyribonucleic Acid (DNA)

Where is DNA located?

Its nucleic acid that located in the cell nucleus.

Does a mitochondria contain DNA?

YES

What is involved in the biosynthesis of proteins?

DNA

The model or structure of DNA it’s described as a double helix. What is a Double Helix?

A helix is a curve, and a double helix is 2 congruent curves connected by horizontal members. It almost resembles a twisted ladder that’s compact.

What does DNA consist of?

Nucleotides

Consist of a five-carbon sugar (pentose), a phosphate group, and a nitrogenous base

What are the 4 types of nitrogenous bases of a DNA?

Adenine (A), Guanine (G), Cytosine (C), Thymine (T)

Out of the 4 types of nitrogenous bases, which of them binds with each other?

Adenine (A) pairs with Thymine (T)

Cytosine (C) pairs with Guanine (G)

How can the 5 bases of DNA and RNA be categorized?

Either as Pyrimidine or Purine according to their structure.

What do Pyrimidine Bases include and what is their shape?

Cytosine, Thymine, and Uracil

They are six-sided and have a single ring shape.

What do Purine Bases include and what is their shape?

Adenine and Guanine

Consists of two attached rings. One ring with 5 sides and the other with 6.

What happens when the 5 bases of DNA and RNA are combined withs sugar?

They become Nucleosides.

Nucleoside formed from purine bases end in “osine” and those formed from pyrimidine bases end in “idine”

What are Codons?

Are groups of 3 nucleotides on the messenger RNA, and can be visualized as 3 rungs of a ladder.

Codon has the code for single amino acid. There are 64 codons but 20 amino acids

What are “Start and Stop Condon”?

They indicate the beginning and ending of a sequence (or frame).

What is an example of Start Condon?

AUG (methionine)

What is an example of Stop Condon?

UAA, UGA, and UAG

Known as ocher, opal, and amber

What are the steps of DNA Replication controlled by?

Enzymes

An example of an enzyme that controls DNA Replication?

Helicase; it instigates the deforming of hydrogen bonds between the bases to split the two strands.

What does the term “Origin of Replication” mean?

It’s used to refer to where the splitting starts

What does the term “Replication Fork” mean?

Portion of the DNA that is unwound to be replicated

What is RNA?

It acts as a helper to DNA and carries out a number of functions

What are the different type of RNA?

Ribosomal RNA (rRNA), Transfer RNA (tRNA), and Messenger RNA (mRNA).

What is the role of Ribosomal RN (rRNA)?

It can be used to study the relationships in organisms and this process hasn’t changed much over time.

What is the role of Messenger RNA (mRNA)?

Carries a copy of a strand of DNA and transports it from the nucleus to the cytoplasm.

What happens during the process of Transcription?

The process in which RNA polymerase copies DNA into RNA.

What happens during the process of Translation?

It’s the process whereby ribosomes use transcribed RNA to put together the needed protein.

What is role of Transfer RNA (tRNA)?

Its a molecule that helps in the translation process, and is found in the cytoplasm.

How does DNA and RNA differ from one another?

In terms of structure and function:

• RNA has different sugar than DNA; Ribose rather than Deoxyribose

• RNA nitrogenous bases are Adenine (A), Guanine (G), Cytosine (C), and Uracil (U). Uracil is only found in RNA, while Thymine (T) is only found in DNA.

• RNA consists of a single strand, while DNA has two.

• It straightened, DNA has two side rails. RNA has one “backbone”, or strand of sugar and phosphate group components.

• RNA supports the functions carried out by DNA, which aids in gene replication, expression, and transportation.