Nucleic Acids Overview
45 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What type of glycosidic bonds connect glucose molecules in amylopectin?

  • β-1,6-glycosidic bonds only
  • α-1,6-glycosidic bonds only
  • α-1,4-glycosidic and α-1,6-glycosidic bonds (correct)
  • β-1,4-glycosidic bonds only

    • Which polysaccharide is not hydrolyzed by human enzymes due to its glycosidic bond type?

  • Dextrins
  • Cellulose (correct)
  • Starch
  • Amylose

    • What are the primary enzymes in human saliva that digest starches?

  • Protease
  • Lipase
  • Cellulase
  • Amylase (correct)

    • Which animal can break down cellulose due to the presence of specific enzymes provided by bacteria in their digestive system?

    <p>Horse</p> Signup and view all the answers

    What is the main difference between amylose and amylopectin structure?

    <p>Amylose is unbranched, while amylopectin is branched.</p> Signup and view all the answers

    What is the most stable form of pentoses and hexoses?

    <p>Five- or six-atom rings</p> Signup and view all the answers

    What does the position of the –OH group on C1 determine in fructose?

    <p>The α or β isomer</p> Signup and view all the answers

    Which carbon determines the sweetness of fructose compared to sucrose?

    <p>C2</p> Signup and view all the answers

    In the formation of the Haworth structure, which group reacts with the carbonyl carbon?

    <p>–OH on C5</p> Signup and view all the answers

    What distinguishes the α and β isomers of D-glucose?

    <p>The orientation of the new –OH group on C1</p> Signup and view all the answers

    What is the five-carbon sugar found in RNA?

    <p>Ribose</p> Signup and view all the answers

    What type of bond is formed between the sugar and phosphate in adjacent nucleotides?

    <p>Phosphodiester bond</p> Signup and view all the answers

    What does the ‘folding’ of the carbon chain into a hexagon represent in sugar chemistry?

    <p>The transformation into a cyclic structure</p> Signup and view all the answers

    Which two carbons are primarily involved in the difference between the structural isomers of fructose?

    <p>C1 and C2</p> Signup and view all the answers

    What characterizes the primary structure of a nucleic acid?

    <p>An alternating sugar and phosphate backbone</p> Signup and view all the answers

    What suffix is added to nucleosides of DNA for differentiation?

    <p>-deoxy</p> Signup and view all the answers

    What structural element forms the corners of the ring in the Haworth structure?

    <p>Carbon atoms</p> Signup and view all the answers

    What is the main difference between the sugars found in DNA and RNA?

    <p>DNA contains deoxyribose, RNA contains ribose</p> Signup and view all the answers

    Which statement about the sugar-phosphate backbone of nucleic acids is true?

    <p>It alternates between sugar and phosphate groups.</p> Signup and view all the answers

    How are the names of nucleosides containing purines generally formed?

    <p>Ending with -osine</p> Signup and view all the answers

    What type of molecules are nucleic acids primarily composed of?

    <p>Nucleotides</p> Signup and view all the answers

    Which of the following monosaccharides is classified as an aldohexose?

    <p>Galactose</p> Signup and view all the answers

    How is the D or L isomer determined in Fischer projections of monosaccharides?

    <p>By the hydroxyl group on the chiral carbon farthest from the carbonyl group</p> Signup and view all the answers

    Which compound's accumulation can lead to galactosemia?

    <p>Galactose</p> Signup and view all the answers

    Which of the following serves as a building block for sucrose and lactose?

    <p>Galactose</p> Signup and view all the answers

    What characterizes D-glucose in terms of its structure?

    <p>It has an aldehyde group at the top in Fischer projection</p> Signup and view all the answers

    Which of the following statements is true about the difference between D-glucose and D-galactose?

    <p>They differ at carbon 4</p> Signup and view all the answers

    Which of the following compounds is identified as a ketopentose?

    <p>Fructose</p> Signup and view all the answers

    What is the direction of the two strands in the sugar-phosphate backbone?

    <p>One strand runs from 5’ to 3’ and the other from 3’ to 5’</p> Signup and view all the answers

    What process must HIV initiate to replicate its genetic material inside the host cell?

    <p>Reverse transcription</p> Signup and view all the answers

    What type of structure do monosaccharides typically form in solution?

    <p>Cyclic structures</p> Signup and view all the answers

    What function does reverse transcriptase serve in retroviruses like HIV?

    <p>Synthesizes DNA from RNA template</p> Signup and view all the answers

    Which drug acts as a nucleoside analog similar to thymidine?

    <p>AZT</p> Signup and view all the answers

    What is the newly formed viral DNA referred to after it integrates with the host cell DNA?

    <p>Provirus</p> Signup and view all the answers

    How does treatment for AIDS typically target HIV-1?

    <p>By inhibiting reverse transcription and protein synthesis</p> Signup and view all the answers

    What role do nucleoside analogs play in the treatment of HIV?

    <p>Mimic structures of nucleosides used for DNA synthesis</p> Signup and view all the answers

    Which of the following is NOT one of the drugs mentioned that act as nucleoside analogs?

    <p>d5T</p> Signup and view all the answers

    Which polysaccharide consists of glucose units joined by α-1,6-glycosidic bonds?

    <p>Glycogen</p> Signup and view all the answers

    What is the main difference between amylose and cellulose?

    <p>Amylose provides energy, while cellulose is not digestible.</p> Signup and view all the answers

    Which statement accurately describes the composition of starch?

    <p>Starch contains α-1,4-glycosidic bonds and is primarily made of D-glucose.</p> Signup and view all the answers

    What is the primary function of glycogen in animals?

    <p>To store energy for later use.</p> Signup and view all the answers

    How are the glucose units in cellulose linked together?

    <p>By β-1,4-glycosidic bonds.</p> Signup and view all the answers

    What percentage of starch is made up of amylose?

    <p>20%</p> Signup and view all the answers

    Which enzyme is responsible for digesting starch in the human body?

    <p>Amylase</p> Signup and view all the answers

    What term is used for the storage form of glucose in plants?

    <p>Starch</p> Signup and view all the answers

    Study Notes

    Nucleic Acids

    • Nucleic acids are large molecules found in cell nuclei, storing information for cellular growth and reproduction.
    • Two main types exist: deoxyribonucleic acid (DNA) and ribonucleic acid (RNA).
    • Both are polymers of repeating monomer units called nucleotides.
    • Each nucleotide has three components: a nitrogenous base, a five-carbon sugar, and a phosphate group.
    • The nitrogenous bases are derivatives of pyrimidine or purine.
    • In RNA, the five-carbon sugar is ribose; in DNA, it's deoxyribose (similar to ribose but without an oxygen atom).
    • Nucleosides are formed by combining a sugar and a base via an N-glycosidic bond.
    • Nucleotides are nucleosides with a phosphate group attached to the sugar's 5' carbon.
    • Only 5'-monophosphate nucleotides are found in DNA and RNA.

    Nucleosides and Nucleotides

    • Nucleosides are combinations of a sugar and a base.
    • Nucleotides include a nucleoside plus a phosphate group.

    Primary Structure of Nucleic Acids

    • Nucleic acids are polymers of nucleotides.
    • Nucleotides are linked by phosphodiester bonds between the 3' hydroxyl group of one sugar and the 5' phosphate group of the next.
    • The sequence of bases forms the primary structure.
    • The sequence is read from the 5' end to the 3' end (5'→3').

    Viruses

    • Viruses are small particles (3-200 genes) requiring a host cell to replicate.
    • They contain either DNA or RNA, but not both.
    • They infect a host cell and use its resources to replicate.

    Reverse Transcription

    • Retroviruses contain RNA as genetic material.
    • They use an enzyme called reverse transcriptase to make DNA from the RNA template.
    • The resulting DNA integrates into the host cell's DNA.
    • Reverse transcriptase inhibitors are used to treat HIV infections.

    Acquired Immune Deficiency Syndrome (AIDS)

    • AIDS is caused by HIV infection.
    • HIV infects T4 lymphocytes (crucial to the immune system).
    • Treatment targets reverse transcription and protein synthesis.
    • Nucleoside analogs mimic normal nucleosides, hindering reverse transcriptase.

    Carbohydrates

    • Carbohydrates are made of carbon, hydrogen, and oxygen.
    • Simple sugars have the formula Cn(H₂O)n, once thought to be hydrated carbons.
    • In photosynthesis, energy from the sun is used to produce carbohydrates.
    • Respiration in cells releases chemical energy from carbohydrates.
    • Monosaccharides are simple sugars, cannot be split further by hydrolysis.
    • Disaccharides form when two monosaccharides combine using a glycosidic bond.
    • Polysaccharides are composed of multiple monosaccharides.

    Types of Carbohydrates

    • Monosaccharides are the simplest form of sugar.
    • Disaccharides combine two monosaccharides.
    • Polysaccharides consist of multiple monosaccharides linked to form long chains.

    Monosaccharides

    • Monosaccharides are sugars with 3-8 carbon atoms.
    • The carbonyl group (aldehyde or ketone) dictates whether it's an aldose or ketose.
    • Monosaccharides are given a 'D' or 'L' designation based on the spatial arrangement around the chiral carbon furthest from the carbonyl group.
    • Monosaccharides form cyclic structures (Haworth projection).
    • Monosaccharides in different ring structures are called anomers (alpha or beta isomers).

    Disaccharides

    • Two monosaccharides joined together by a glycosidic bond.
    • Different glycosidic bonds lead to different disaccharides (maltose, sucrose, lactose).
    • Lactose (milk sugar)
    • Sucrose (table sugar)
    • Maltose (malt sugar)

    Polysaccharides

    • Long chains of monosaccharides linked by glycosidic bonds.
    • Starch, glycogen, and cellulose are major polysaccharides in various roles.
    • Starch (plants): storage form of glucose, has amylose and amylopectin.
    • Glycogen (animals): storage form of glucose, highly branched.
    • Cellulose (plants): structural component, humans cannot digest.

    Other Important Carbohydrates

    • Fructose (fruit sugar): a ketohexose, sweeter than glucose
    • Galactose: aldohexose that differs from glucose only at one carbon.

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Related Documents

    BBIO109 Lecture Notes: Nucleic Acids & Carbohydrates PDF

    Description

    Explore the fundamental concepts of nucleic acids, including DNA and RNA. Learn about their structures, components like nucleotides and nucleosides, and their roles in cellular processes. This quiz covers key molecular biology concepts pertinent to nucleic acids.

    More Like This

    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser