Nutritional Biochemistry Genetics Quiz

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

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

<p>10.5 steps (A)</p> Signup and view all the answers

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

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

<p>Joining of Okazaki fragments (C)</p> Signup and view all the answers

<p>3ʹ-5ʹ phosphodiester bond (A)</p> Signup and view all the answers

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

<p>To direct the synthesis of proteins (B)</p> Signup and view all the answers

<p>In opposite directions (B)</p> Signup and view all the answers

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

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

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

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

<p>General transcription factors (A)</p> Signup and view all the answers

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

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

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

<p>Hormones and growth factors (D)</p> Signup and view all the answers

<p>To help compact DNA (D)</p> Signup and view all the answers

<p>A discrete segment of DNA encoding an amino acid sequence (B)</p> Signup and view all the answers

<p>To locate RNA polymerase at the initiation site (C)</p> Signup and view all the answers

<p>They bind to transcription factors to enhance gene activation (C)</p> Signup and view all the answers

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

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

<p>It dissociates from the DNA (C)</p> Signup and view all the answers

<p>Exons are protein-coding sequences, introns are non-coding (C)</p> Signup and view all the answers

<p>Ribosomes and transfer RNA (tRNA) (C)</p> Signup and view all the answers

<p>From proteins associated with ribosomal RNA (rRNA) (C)</p> Signup and view all the answers

<p>Large and small subunits (A)</p> Signup and view all the answers

<p>Clover leaf structure (A)</p> Signup and view all the answers

<p>Either the A or P site (B)</p> Signup and view all the answers

<p>It binds to the complementary triplet code on mRNA (D)</p> Signup and view all the answers

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

<p>Presence of a stop codon (A)</p> Signup and view all the answers

<p>From the mRNA (A)</p> Signup and view all the answers

<p>Tricarboxylic Acid Cycle (TCA) (B)</p> Signup and view all the answers

<p>Cellular acidosis due to anaerobic ATP production (B)</p> Signup and view all the answers

<p>They damage mtDNA, affecting ATP production in dopaminergic neurons. (A)</p> Signup and view all the answers

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

<p>A double helix formed by phosphodiester bonds between nucleotides. (C)</p> Signup and view all the answers

<p>Nuclear DNA is located in the nucleus while mitochondrial DNA is not. (B)</p> Signup and view all the answers

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

<p>The point of separation for the two strands of DNA during replication. (C)</p> Signup and view all the answers

<p>Point mutations in mtDNA have been observed in some cancers. (B)</p> Signup and view all the answers

The complete genetic information of an organism, contained in every cell. It guides the cell's activities based on stimuli and transmits inherited traits.

DNA is a polymer constructed from monomers called nucleotides. Its structure is a double helix, like a twisted ladder, with a width of 2 nm and 10.5 'steps' per turn.

Adenine (A) pairs with Thymine (T), and Guanine (G) pairs with Cytosine (C). These pairs are held together by hydrogen bonds, with two bonds between A and T, and three between G and C.

Nucleotides are the building blocks of DNA. Each nucleotide consists of a sugar molecule (deoxyribose), a nitrogenous base (adenine, thymine, guanine, or cytosine), and a phosphate group.

Polynucleotides are long chains of nucleotides linked together, forming the structural units of DNA.

The process of copying DNA, ensuring each new cell receives a complete copy of the genome.

The process of transcribing genetic information from DNA into RNA.

The process of translating genetic information from RNA into proteins, the building blocks of life.

In DNA, the 5' end of a nucleotide forms a bond with the 3' end of the next nucleotide, eliminating the OH group of the 3' carbon. This bond, called a 3'-5' phosphodiester bond, links the sugar-phosphate backbone of DNA.

The two strands of DNA run in opposite directions, like a one-way street. One strand runs 5' to 3', the other runs 3' to 5'. This is essential for DNA replication.

DNA is tightly packaged inside the nucleus. It wraps around histone proteins, forming nucleosomes, which are further condensed into chromatin fibers, and ultimately organized into chromosomes.

Histones are modified by enzymes to regulate gene transcription. These modifications are known as epigenetics, influencing gene expression without altering the DNA sequence.

A gene is a segment of DNA that contains the instructions for building a specific protein. Genes are found on chromosomes and are the basic units of inheritance.

Telomeres are protective caps at the ends of chromosomes. They consist of repetitive DNA sequences that prevent degradation and fusion with other chromosomes.

The cell cycle encompasses a series of events leading to cell division. DNA replication occurs during a specific phase of the cell cycle, ensuring that each daughter cell receives a copy of the genetic material.

The 5' end of a DNA strand is characterized by a phosphate group, while the 3' end has a hydroxyl group. This difference is essential for DNA polymerase to add new nucleotides during replication.

The process of joining Okazaki fragments on the lagging strand during DNA replication. This step is crucial to create a continuous DNA strand.

A type of nucleic acid that carries the genetic information from DNA to ribosomes, where protein synthesis takes place.

A region on DNA where transcription starts. It contains binding sites for transcription factors, which regulate the rate of gene transcription.

Proteins that bind to DNA and regulate the transcription of genes. They control the rate at which a gene is transcribed.

The process of copying DNA, ensuring each new cell receives a complete copy of the genome.

The process of converting the genetic information in DNA into RNA.

The process of converting the genetic information in RNA into proteins.

A small section of DNA that contains the instructions for making a specific protein. They are essential for directing cellular functions.

DNA sequences that enhance gene transcription by binding to transcription factors. They can be located far from the gene they regulate.

A promoter sequence located about 25-30 base pairs upstream of the transcription start site in a significant portion of genes. It helps RNA polymerase find the correct starting point for transcription.

The enzyme responsible for synthesizing RNA from a DNA template. It reads the DNA sequence and adds complementary RNA nucleotides one by one.

The process of adding nucleotides to a growing RNA chain, following the sequence of the DNA template.

The process of ending RNA synthesis. It occurs when RNA polymerase encounters a specific DNA sequence that signals the end of the RNA molecule.

Regions within a gene that code for protein sequences.

Regions within a gene that do not code for proteins and are removed from the pre-mRNA during splicing.

The process of removing introns and joining exons together in a pre-mRNA molecule, creating a mature mRNA molecule ready for translation.

Ribosomes consist of two subunits: a large subunit and a small subunit. These subunits are separate in the cytosol but combine during protein synthesis.

Ribosomes are the site of protein synthesis. They read messenger RNA (mRNA) and add amino acids based on the three-base code (codon) on the mRNA.

Transfer RNA (tRNA) has a cloverleaf shape and carries specific amino acids. It has an anticodon that binds to the complementary codon on mRNA, bringing the amino acids in the correct order.

The triplet code refers to the three-base sequence (codon) on mRNA that codes for a specific amino acid.

The process of adding amino acids to a growing polypeptide chain is called elongation. The second tRNA binds to the ribosome, and the adjacent amino acids are joined by peptide bonds.

Protein synthesis ends when a stop codon is reached on the mRNA. At this point, the completed polypeptide is released, and the ribosome detaches from the mRNA.

Mitochondria are responsible for producing most of a cell's energy (ATP) through oxidative phosphorylation. They also house important biochemical pathways, like the citric acid cycle and part of the urea cycle.

Mitochondrial DNA (mtDNA) is unique because it is separate from the cell's nuclear DNA. It plays a crucial role in energy production within the mitochondria.

In tissues with high metabolic demand, like the brain, heart, and skeletal muscle, pyruvate is shunted to lactate to produce ATP anaerobically. This leads to a buildup of acid in the cells (acidosis). It's like your muscles burning during strenuous exercise.

Mitochondrial DNA (mtDNA) mutations are linked to Parkinson's disease, particularly affecting the substantia nigra, the brain region responsible for controlling movement. These mutations disrupt the production of ATP in dopaminergic neurons.

MtDNA mutations are also associated with cancer, but their precise role is not entirely clear. While there is evidence of point mutations in mtDNA in some cancers, the impact of these mutations on cancer development remains under investigation.

A nucleotide consists of three components: a nitrogenous base (adenine, guanine, cytosine, thymine), a pentose sugar (deoxyribose in DNA, ribose in RNA), and a phosphate group. These nucleotides link together to form polynucleotide chains.

DNA is tightly wrapped around histone proteins, forming nucleosomes. These nucleosomes are further condensed into chromatin fibers, which are then organized into chromosomes. This packaging allows the vast DNA molecule to fit within the nucleus of a cell.

DNA undergoes transcription, where genetic information is copied from DNA to RNA, and translation, where RNA is used as a blueprint to create proteins. Both processes involve enzymes that regulate their steps.

A replication fork is a Y-shaped structure formed during DNA replication. It represents the point where the two strands of the DNA double helix are unwound and separated. DNA synthesis occurs in a 5' to 3' direction on both strands, with one strand being synthesized continuously and the other discontinuously in fragments called Okazaki fragments.