Introduction to Molecular Biology 1

<p>Messenger RNA (C)</p> Signup and view all the answers

<p>DNA -&gt; RNA -&gt; Protein (B)</p> Signup and view all the answers

<p>Dr. Phoebus Levene (D)</p> Signup and view all the answers

<p>The secondary structure formation (D)</p> Signup and view all the answers

<p>Uracil (D)</p> Signup and view all the answers

<p>Presence of phosphate groups (D)</p> Signup and view all the answers

<p>260 nanometers (C)</p> Signup and view all the answers

<p>DNA double strand unwinds (B)</p> Signup and view all the answers

<p>C-G pairs due to three hydrogen bonds (D)</p> Signup and view all the answers

<p>Negative (B)</p> Signup and view all the answers

<p>High temperature (D)</p> Signup and view all the answers

<p>When temperature is decreased (D)</p> Signup and view all the answers

<p>Half of the DNA molecule is denatured (C)</p> Signup and view all the answers

<p>Alternating phosphate and sugar (D)</p> Signup and view all the answers

<p>3’ and 5’ (B)</p> Signup and view all the answers

<p>Phosphate groups (D)</p> Signup and view all the answers

<p>Nucleotide has phosphate (B)</p> Signup and view all the answers

<p>5’ to 3’ (C)</p> Signup and view all the answers

<p>Major: deep and wide; Minor: narrow and shallow (C)</p> Signup and view all the answers

<p>260 nm (A)</p> Signup and view all the answers

<p>Forming the backbone of DNA (D)</p> Signup and view all the answers

<p>To store and pass on genetic information (B)</p> Signup and view all the answers

<p>In a spiral staircase or twisted ladder shape (B)</p> Signup and view all the answers

<p>Deoxyribose, phosphate, nitrogenous bases (A)</p> Signup and view all the answers

<p>Deoxyribose lacks a hydroxyl group at carbon 2’ (B)</p> Signup and view all the answers

<p>One phosphorus and four oxygen atoms (A)</p> Signup and view all the answers

<p>Deoxyribose and phosphate (D)</p> Signup and view all the answers

<p>Pentose sugar (A)</p> Signup and view all the answers

<p>It is key for describing the directionality of DNA (D)</p> Signup and view all the answers

<p>Phosphodiester bonds (C)</p> Signup and view all the answers

<p>5' and 3' carbons (D)</p> Signup and view all the answers

<p>Ribose is a pentose sugar found in RNA (A)</p> Signup and view all the answers

<p>Pairs of nitrogenous bases (A)</p> Signup and view all the answers

<p>Uracil (C)</p> Signup and view all the answers

<p>Ester bonds (D)</p> Signup and view all the answers

<p>Thymine with Adenine (A), Guanine with Cytosine (D)</p> Signup and view all the answers

<p>Nitrogenous bases (C)</p> Signup and view all the answers

<p>Adenine percentage equals thymine percentage, and guanine percentage equals cytosine percentage. (A)</p> Signup and view all the answers

<p>DNA is a helical structure with a consistent width. (A)</p> Signup and view all the answers

<p>They arranged nucleotides with complementary base pairing. (C)</p> Signup and view all the answers

<p>1949 (D)</p> Signup and view all the answers

<p>The structure is stabilized by hydrogen bonds between opposite bases. (B)</p> Signup and view all the answers

<p>Salmon (B)</p> Signup and view all the answers

<p>The ratios of certain nucleotides are equal across many species. (B)</p> Signup and view all the answers

<p>By using Chargaff's rule to pair nucleotides together. (A)</p> Signup and view all the answers

Molecular biology emerged in the 1930s and 1940s, combining the work of different fields towards understanding the nature of inheritance.

Swiss chemist Friedrich Miescher first identified DNA in the late 1860s, calling it "nuclein."

The term "molecular biology" was coined by Warren Weaver in 1938 and the field gained momentum in the 1950s and 1960s.

In 1950, Erwin Chargaff discovered that in DNA, the ratios of adenine (A) to thymine (T) and guanine (G) to cytosine (C) are equal.

In 1953, James Watson and Francis Crick discovered the double helical structure of the DNA molecule.

In 1961, Francois Jacob and Jacques Monod discovered messenger RNA (mRNA), an intermediary between DNA and protein production.

The central dogma describes the flow of genetic information from DNA to RNA to protein.

DNA (Deoxyribonucleic acid) is a double-stranded nucleic acid composed of a deoxy sugar backbone and nitrogenous bases: adenine, cytosine, guanine, and thymine.

The principle that in DNA, the amount of adenine (A) always equals the amount of thymine (T), and the amount of guanine (G) always equals the amount of cytosine (C).

A technique that uses X-rays to create images of molecules, revealing their structure. It was crucial for understanding the double helix structure of DNA.

The consistent width of the DNA molecule observed through X-ray diffraction, suggesting the presence of a double helix.

The repeating pattern within DNA observed through X-ray diffraction, indicating a helical structure.

The arrangement of base pairs (A-T and G-C) in DNA, where the strands run in opposite directions.

The structure of DNA where two strands are intertwined, forming a helical shape.

The hydrogen bonds between base pairs (A-T and G-C) and the stacking interactions of bases contribute to the stability of the double helix.

The discovery that DNA is composed of two strands running in opposite directions, essential for DNA replication and gene expression.

DNA is a crucial molecule responsible for carrying and transmitting genetic information from one generation to the next, ensuring that traits and characteristics are inherited.

DNA's structure resembles a twisted ladder or a spiral staircase, with two strands of nucleotides winding around each other.

DNA is composed of three main building blocks: deoxyribose sugar, phosphate groups, and nitrogenous bases.

Deoxyribose is a five-carbon sugar, similar to glucose but with one less oxygen atom. It forms the backbone of the DNA molecule.

Phosphate groups are negatively charged molecules that link deoxyribose sugars in the DNA backbone.

Nitrogenous bases are molecules that attach to the deoxyribose sugar and store genetic information. There are four main types: adenine (A), guanine (G), cytosine (C), and thymine (T).

Ribose is a five-carbon sugar found in RNA. It differs from deoxyribose by having an extra hydroxyl (-OH) group attached to the 2' carbon.

The carbon atoms in ribose and deoxyribose are numbered clockwise from 1' to 5'. This numbering system helps describe the directionality of the DNA strand.

The ability of DNA to dissolve in water due to its hydrophilic phosphate groups.

The absorption of ultraviolet light by DNA bases, particularly at 260 nanometers, which can be measured using a spectrophotometer.

The process of DNA unwinding into single strands when exposed to factors like high temperature or extreme pH.

The process of single-stranded DNA molecules rejoining to form a double helix upon cooling after denaturation.

The temperature at which half of the DNA molecule is denatured, influenced by the content of guanine-cytosine (G-C) base pairs.

DNA is negatively charged due to the phosphate groups in its backbone.

The two strands of DNA run in opposite directions, forming a helical structure.

The basic structural unit of DNA, composed of a deoxyribose sugar molecule, a phosphate group, and a nitrogenous base.

The two strands of DNA run in opposite directions. One strand runs 5' to 3', and the other runs 3' to 5'. This arrangement is crucial for DNA replication and transcription.

The sequence of nitrogenous bases (A, T, G, C) in DNA determines the genetic code. A and T always pair together, and G and C always pair together.

The temperature at which 50% of the DNA molecules in a solution have denatured.

The sugar molecule in DNA, with one less oxygen atom compared to ribose (found in RNA).

The backbone of the DNA molecule is made up of alternating phosphate and sugar units, connected by phosphodiester bonds.

The negatively charged phosphate groups in the DNA backbone give DNA a negative charge.

A phosphate group is a chemical group that consists of a phosphorus atom bonded to four oxygen atoms. It is a common component of many organic molecules, including nucleic acids like DNA and RNA, and is crucial for energy transfer within cells.

In DNA and RNA, the phosphate group is attached to the sugar molecule at the 5' carbon position.

The DNA backbone is formed by alternating sugar molecules (deoxyribose) and phosphate groups connected by ester bonds or phosphodiester bonds.

Ester bonds are chemical bonds formed between a hydroxyl group (OH) of a sugar and a phosphate group. These bonds are crucial for linking the sugar and phosphate units in the DNA backbone.

Phosphodiester bonds are strong covalent bonds that link phosphate groups to sugar molecules in DNA and RNA, forming the backbone of these nucleic acids. They are essential for the stability and functionality of DNA and RNA.

The DNA backbone is formed by connecting the 5' carbon of one deoxyribose sugar to the 3' carbon of the next sugar through a phosphate group. This creates a directional backbone, with a 5' end and a 3' end.

The two strands of DNA are called the Watson strand and the Crick strand, which are antiparallel (running in opposite directions), forming a double helix.

The 'steps' of the DNA ladder are formed by pairs of nitrogenous bases, specifically adenine (A) paired with thymine (T) and guanine (G) paired with cytosine (C).