BIOCHEM 1.1

• What is the biological role of magnesium ions (Mg$^{2+}$)?


  Part of chlorophyll and essential for photosynthesis
• What is the biological role of iron ions (Fe$^{2+}$)?


  Part of haemoglobin, which transports oxygen in red blood cells
• What is the biological role of nitrate ions (NO$_{3}^{-}$)?


  Nitrogen from nitrate is needed for making nucleotides, including ATP, DNA, and RNA
• What is the biological role of phosphate ions (PO$_{4}^{3-}$)?


  Used for making nucleotides, including ATP, DNA, and RNA
• What is the biological role of calcium ions (Ca$^{2+}$)?


  Hardens bones and teeth and is a component of plant cell walls
• What are inorganic ions often referred to as?

  Minerals
• What are micronutrients?

  The essential nutrients that the body requires in small amounts to function properly.
• What are macronutrients?

  Nutrients that the body needs in larger amounts to provide energy and support bodily functions.
• What is the general formula for monosaccharides?

  (CH$_{2}$O)$_{n}$
• What is a dipole in the context of water molecules?

  A polar molecule with a positive and negative charge separated by a small distance
• What is a hydrogen bond?

  The weak attractive force between a hydrogen atom and an atom with a partial negative charge

  
• What is cohesion in water molecules?

  The attraction between water molecules that allows them to form a lattice-like framework
• What are the properties of water and their functions?

  • Water is a solvent: Attracts charged particles and dissolves ions and polar molecules.
  • Water as a transport medium: Transports dissolved substances in blood and plants.
  • Chemical reactions take place in water: Facilitates reactions when particles meet.
  • High specific heat capacity: Prevents large temperature fluctuations in aquatic environments.
  • High latent heat of vaporisation: Effective cooling mechanism through evaporation.
  • Cohesion: Allows water to be transported in xylem vessels.
  • Surface tension: Supports small organisms on water surfaces.
  • Density: Ice floats, insulating water below and allowing organisms to survive.
• What is the function of triose monosaccharides?

  Important in metabolism as intermediates in respiration and photosynthesis
• What is the function of pentose monosaccharides?

  Constituents of nucleotides such as deoxyribose in DNA and ribose in RNA
• What is the function of hexose monosaccharides?

  Glucose is a source of energy in respiration
• What are isomers?

  • Same chemical formula and number of atoms
  • Atoms arranged differently
  • Example: α glucose and β glucose
• What is the process of forming disaccharides?

  • Composed of two monosaccharide sub-units
  • Formed by glycosidic bond and elimination of water
  • Example: Maltose from two α glucose molecules

  
• What is the role of Benedict's reagent in testing for reducing sugars?

  Benedict's reagent reduces blue copper(II) sulfate to form a brick-red precipitate
• Why is sucrose considered a non-reducing sugar?

  It does not reduce copper(II) sulfate without hydrolysis
• What are the characteristics of polysaccharides?

  • Large complex polymers
  • Formed from many identical monosaccharide units
  • Linked by glycosidic bonds through condensation reactions
  • Examples: Starch, glycogen, cellulose
• What is the difference between amylose and amylopectin?

  Amylose is unbranched and coils, while amylopectin is branched

  
• What is the main storage product in animals?

  Glycogen
• What is the structure of cellulose?

  Consists of long, parallel chains of β glucose units joined by C1–C4 glycosidic bonds

  
• What is chitin and where is it found?

  A structural polysaccharide found in the exoskeleton of arthropods and fungal cell walls
• What are triglycerides and their characteristics?

  • Common types of lipids (fats and oils)
  • Formed by condensation reaction between glycerol and fatty acids
  • Insoluble in water, soluble in organic solvents
  • Contain three ester bonds

  
• What distinguishes unsaturated fatty acids from saturated fatty acids?

  Unsaturated fatty acids have double bonds between carbon atoms, while saturated do not
• What are the main causes of heart disease related to lipids?

  Fatty deposits in coronary arteries and high blood pressure
• What happens when food is absorbed in the small intestine regarding lipids?

  Lipids and proteins combine to make lipoproteins that travel in the bloodstream
• What is the significance of the ester bond in triglycerides?

  • Formed by condensation reaction between glycerol and fatty acids
  • Three ester bonds in a triglyceride
  • Can be broken by hydrolysis

  
• What type of bonds exist between neighboring carbon atoms in a saturated fatty acid?

  Single bonds
• What does a saturated fatty acid carry?

  The maximum possible number of hydrogen atoms
• What is the physical state of saturated fatty acids at room temperature?

  They are solid
• Which type of lipids tend to be saturated?

  Animal lipids
• What is a possible health concern linked to the consumption of saturated fatty acids?

  Heart disease
• What are the main causes of heart disease mentioned in the material?

  Fatty deposits in coronary arteries and high blood pressure
• What dietary factors contribute to heart disease?

  A diet high in saturated fatty acids, smoking, lack of exercise, and aging
• What happens to lipids and proteins after food absorption in the small intestine?

  They combine to make lipoproteins
• What is the consequence of a diet high in saturated fats regarding lipoproteins?

  Low-density lipoproteins (LDL) build up
• What is atheroma and its effect on coronary arteries?

  Fatty material that restricts blood flow