All flashcards
Flashcard 1: What is the main cellular consequence of a change in a protein's amino acid sequence?
Answer: Altered folding and function, potentially changing cell phenotype. Protein shape changes can disrupt enzyme activity or binding.
Flashcard 2: What is an enhancer and what is its effect on molecular synthesis?
Answer: A DNA element that increases transcription when bound by activators. Enhancers can work from distant locations to boost transcription.
Flashcard 3: What is the central dogma that links molecular synthesis to cellular function?
Answer: DNA is transcribed to RNA, and RNA is translated to protein. This fundamental principle describes the flow of genetic information in cells.
Flashcard 4: What is transcription in terms of molecular synthesis?
Answer: Synthesis of RNA from a DNA template. RNA polymerase reads DNA template to create complementary RNA strand.
Flashcard 5: What is translation in terms of molecular synthesis?
Answer: Synthesis of a polypeptide using an mRNA template. Ribosomes decode mRNA codons to assemble amino acids into proteins.
Flashcard 6: What is the direct product of translation that can affect cell structure and function?
Answer: A polypeptide (protein primary structure). This linear chain of amino acids determines protein folding and function.
Flashcard 7: Which organelle is the primary site of protein synthesis for cytosolic proteins?
Answer: Free ribosomes in the cytosol. These ribosomes make proteins that function within the cytoplasm.
Flashcard 8: Which organelle synthesizes proteins destined for secretion or membranes?
Answer: Ribosomes bound to rough endoplasmic reticulum. The rough ER directs proteins to secretory or membrane pathways.
Flashcard 9: What is the role of mRNA in connecting gene sequence to cell function?
Answer: It carries the coding information from DNA to ribosomes. mRNA acts as a messenger between nuclear DNA and cytoplasmic ribosomes.
Flashcard 10: What is the role of tRNA in protein synthesis and cellular function?
Answer: It matches anticodons to codons and delivers amino acids. tRNA serves as the adapter molecule in the genetic code translation.
Flashcard 11: What is the role of rRNA in translation?
Answer: It forms the ribosome and catalyzes peptide bond formation. rRNA is both structural and enzymatic component of ribosomes.
Flashcard 12: What is a codon and how does it connect nucleic acid sequence to protein function?
Answer: A 3-base mRNA sequence that specifies an amino acid or stop. The genetic code links DNA sequence to protein amino acid sequence.
Flashcard 13: What is the start codon used to initiate translation in most organisms?
Answer: AUG (codes for methionine). This universal start signal ensures proper translation initiation.
Flashcard 14: What is the function of a stop codon in translation?
Answer: It signals termination of translation and release of the polypeptide. UAA, UAG, and UGA codons halt translation when reached.
Flashcard 15: Which base in RNA replaces thymine and how does that affect transcription products?
Answer: Uracil (U) replaces thymine (T) in RNA. This base-pairing difference distinguishes RNA from DNA structure.
Flashcard 16: What type of bond links amino acids during protein synthesis?
Answer: Peptide bonds. These covalent bonds connect amino acids in the protein backbone.
Flashcard 17: What level of protein structure is determined directly by the amino acid sequence?
Answer: Primary structure. The amino acid sequence directly determines all higher protein structures.
Flashcard 18: What is the main cellular consequence of a change in a protein's amino acid sequence?
Answer: Altered folding and function, potentially changing cell phenotype. Protein shape changes can disrupt enzyme activity or binding.
Flashcard 19: What is a gene in the context of molecular synthesis and cellular function?
Answer: A DNA sequence that encodes a functional RNA or protein product. Genes are the basic units of heredity that direct cell functions.
Flashcard 20: What is a promoter and how does it influence cellular function?
Answer: A DNA region where RNA polymerase binds to start transcription. Promoters control when and how much RNA is transcribed.
Flashcard 21: Which option best connects a DNA mutation to altered cell function: silent, missense, or nonsense mutation?
Answer: Nonsense mutation (introduces a premature stop codon). Nonsense mutations create truncated, usually nonfunctional proteins.
Flashcard 22: Identify the polysaccharide synthesized for plant cell wall structure.
Answer: Cellulose. This structural polysaccharide provides plant cell rigidity.
Flashcard 23: Identify the polysaccharide synthesized for energy storage in animals.
Answer: Glycogen. Animals store glycogen primarily in liver and muscle.
Flashcard 24: Identify the polysaccharide synthesized for energy storage in plants.
Answer: Starch. Plants synthesize starch in chloroplasts and amyloplasts.
Flashcard 25: What is the main function of cholesterol in animal cell membranes?
Answer: It modulates membrane fluidity and stability. Cholesterol helps maintain optimal membrane properties.
Flashcard 26: Identify the molecule synthesized to store energy long-term in many animals.
Answer: Triglycerides (fats). These lipids store more energy per gram than carbohydrates.
Flashcard 27: What is hydrolysis and what is its effect on polymers in cells?
Answer: Addition of water to break polymers into monomers. This process breaks down macromolecules for cellular use.
Flashcard 28: What is dehydration synthesis and which bond does it form between monosaccharides?
Answer: Removal of water to form a glycosidic bond. This process links monosaccharides into larger carbohydrates.
Flashcard 29: Which macromolecule class is synthesized for short-term energy storage and cell ID?
Answer: Carbohydrates. These molecules provide quick energy and cellular recognition.
Flashcard 30: Which macromolecule class is synthesized to provide structure and catalysis?
Answer: Proteins. Proteins perform most cellular work including catalysis and structure.