All flashcards
Flashcard 1: What 2-carbon molecule is formed from pyruvate before entering the citric acid cycle?
Answer: Acetyl-CoA. Pyruvate loses CO2 and combines with coenzyme A.
Flashcard 2: Which monosaccharide is commonly polymerized to form starch, glycogen, and cellulose?
Answer: Glucose. This 6-carbon sugar is the most common polysaccharide monomer.
Flashcard 3: What is the name of the bond formed when nucleotides join to extend a nucleic acid strand?
Answer: Phosphodiester bond. These bonds link phosphate to sugar in nucleic acid backbones.
Flashcard 4: Which pentose sugar is found in RNA nucleotides?
Answer: Ribose. This 5-carbon sugar has hydroxyl groups on carbons 2 and 3.
Flashcard 5: What type of reaction links monomers to form polymers by removing water?
Answer: Dehydration (condensation) reaction. Water removal creates covalent bonds between monomers.
Flashcard 6: What type of reaction breaks polymers into monomers by adding water?
Answer: Hydrolysis. Water addition breaks covalent bonds in polymers.
Flashcard 7: Which macromolecule is synthesized directly by linking monosaccharides together?
Answer: Polysaccharides (carbohydrates). Sugar monomers link together to form complex carbohydrates.
Flashcard 8: What bond type links monosaccharides during polysaccharide synthesis?
Answer: Glycosidic bond. This covalent bond forms between sugar hydroxyl groups.
Flashcard 9: Which monosaccharide is commonly polymerized to form starch, glycogen, and cellulose?
Answer: Glucose. This 6-carbon sugar is the most common polysaccharide monomer.
Flashcard 10: What are the building blocks (monomers) used to synthesize proteins from carbon skeletons?
Answer: Amino acids. These molecules contain carbon skeletons plus amino groups.
Flashcard 11: What bond links amino acids during protein synthesis?
Answer: Peptide bond. This covalent bond links amino acids in protein chains.
Flashcard 12: What is the 3-carbon end product of glycolysis that serves as a key carbon skeleton?
Answer: Pyruvate. This molecule can be converted into many different biomolecules.
Flashcard 13: Which elements must be added to a carbon skeleton to form an amino acid?
Answer: Nitrogen (and often sulfur) in addition to C, H, and O. Additional atoms beyond carbon, hydrogen, and oxygen are required.
Flashcard 14: What process adds an amino group to a carbon skeleton to help form amino acids?
Answer: Amination (nitrogen assimilation into carbon skeletons). This process incorporates nitrogen into organic molecules.
Flashcard 15: What is the primary inorganic nitrogen source plants assimilate to build amino acids?
Answer: Nitrate (NO3−) (often reduced to ammonium before incorporation). Plants reduce this compound to incorporate nitrogen into amino acids.
Flashcard 16: What is the immediate nitrogen form commonly incorporated into amino acids in cells?
Answer: Ammonium (NH4+). This reduced nitrogen form directly enters amino acid synthesis.
Flashcard 17: Which cycle generates many carbon skeleton intermediates used in biosynthesis?
Answer: Citric acid cycle (Krebs cycle). This cycle produces multiple carbon compounds for biosynthesis.
Flashcard 18: Which macromolecule class requires nitrogenous bases, a sugar, and phosphate groups?
Answer: Nucleic acids (DNA and RNA). These polymers require sugar, nitrogen, and phosphorus components.
Flashcard 19: What are the monomers used to synthesize nucleic acids from sugars?
Answer: Nucleotides. These building blocks contain sugar, phosphate, and nitrogenous base.
Flashcard 20: What is the name of the metabolic pathway that splits glucose into two 3-carbon molecules?
Answer: Glycolysis. This pathway breaks glucose into two pyruvate molecules.
Flashcard 21: Which process breaks sugars into smaller carbon skeletons that can be rebuilt into biomolecules?
Answer: Cellular respiration (glycolysis and the citric acid cycle). These pathways break glucose into reusable carbon building blocks.
Flashcard 22: Which process directly produces sugars that can be used to synthesize carbon-based molecules?
Answer: Photosynthesis (Calvin cycle sugar production). The Calvin cycle fixes CO2 into glucose and other sugars.
Flashcard 23: What is a carbon skeleton in metabolism?
Answer: A chain or ring of carbon atoms that forms the backbone of an organic molecule. The structural framework provides attachment points for functional groups.
Flashcard 24: What bond links nucleotides together in a nucleic acid polymer?
Answer: Phosphodiester bond. This bond connects sugar and phosphate groups between nucleotides.
Flashcard 25: Which pentose sugar is found in RNA nucleotides?
Answer: Ribose. This 5-carbon sugar has hydroxyl groups on carbons 2 and 3.
Flashcard 26: Which pentose sugar is found in DNA nucleotides?
Answer: Deoxyribose. This sugar lacks a hydroxyl group on carbon 2.
Flashcard 27: Which macromolecule class is synthesized by assembling fatty acids and glycerol?
Answer: Lipids (for example, triglycerides and phospholipids). These molecules are built from sugar-derived glycerol and fatty acids.
Flashcard 28: What is the 3-carbon alcohol backbone used to build triglycerides from sugar-derived carbon?
Answer: Glycerol. This molecule can be derived from sugar metabolism.
Flashcard 29: What type of bond forms when a fatty acid attaches to glycerol during triglyceride synthesis?
Answer: Ester linkage (ester bond). This bond forms when carboxyl groups react with hydroxyl groups.
Flashcard 30: Which sugar-derived molecule commonly provides 2-carbon units for fatty acid synthesis?
Answer: Acetyl-CoA. This molecule provides carbon units for fatty acid chain elongation.