Biology

• What is the focus of the video summarized in the study material?


  The video summarizes everything needed for the AQA A Level Biology topic of biological molecules.
• What should students do while watching the video?

  Students should download a checklist from the website and tick off what they are confident with.
• How can students assess their understanding of the video content?

  By following links on the website to fill in knowledge gaps.
• What is the first topic covered in AQA A Level Biology?

  • Biological molecules
  • Required for both AS papers and A Level paper 1 and paper 3
• What types of bonding are discussed in relation to biological molecules?

  There are covalent bonding, ionic bonding, and hydrogen bonding.
• What is covalent bonding?


  Covalent bonding is the sharing of electrons between two non-metals.
• What is ionic bonding?

  Ionic bonding is the transfer of electrons from a metal to a non-metal, forming positive and negative ions.
• What is hydrogen bonding?


  Hydrogen bonding is a weak attraction between opposite dipoles, such as between hydrogen and oxygen in water.
• How does water illustrate hydrogen bonding?

  In water, the hydrogen atoms are slightly positive and the oxygen atom is slightly negative, leading to attraction.
• What is the difference between covalent bonds and hydrogen bonds?

  Covalent bonds are strong intra-molecular bonds, while hydrogen bonds are weak inter-molecular bonds.
• What are monomers and polymers?

  • Monomers: single units (e.g., amino acids, nucleotides, glucose)
  • Polymers: chains of monomers (e.g., proteins, DNA, polysaccharides)
• What does the term "monomer" mean?


  A monomer is one bit of something, such as an amino acid.
• What does the term "polymer" mean?


  A polymer is many bits of something, formed from multiple monomers.
• What is an example of a monomer that can polymerize into proteins?

  Amino acids can polymerize into proteins.
• What is an example of a monomer that can polymerize into nucleic acids?

  Nucleotides can polymerize into nucleic acids.
• What is an example of a monomer that can polymerize into carbohydrates?

  Glucose can polymerize into polysaccharides or carbohydrates.
• What are hydrolysis and condensation reactions?

  • Hydrolysis: breaks chemical bonds using water.
  • Condensation: joins two molecules together, eliminating water.
• What does hydrolysis do to a dipeptide?

  Hydrolysis breaks the bond between two amino acids in a dipeptide using water.
• What happens during a condensation reaction involving amino acids?

  A condensation reaction joins amino acids together to form a polypeptide, eliminating water.
• What is the general formula for monosaccharides?

  The general formula for monosaccharides is $C_nH_{2n}O_n$.
• What are some examples of monosaccharides?

  Examples of monosaccharides include glucose, galactose, and fructose.
• What is the difference between alpha glucose and beta glucose?

  Alpha glucose and beta glucose have the same formula but differ in the arrangement of the hydrogen and hydroxyl groups.
• What is the formula for both alpha and beta glucose?

  The formula for both alpha and beta glucose is $C_6H_{12}O_6$.
• Why is the spatial arrangement of alpha and beta glucose important?

  The spatial arrangement affects their properties and how they interact in biological systems.
• How do alpha glucose and beta glucose differ structurally?

  • Alpha glucose: hydroxyl group (OH) is below the plane.
  • Beta glucose: hydroxyl group (OH) is above the plane.
• What is a disaccharide?

  A disaccharide is two monosaccharides joined together.
• What is the bond formed between two monosaccharides in a disaccharide called?

  The bond is called a glycosidic bond.
• What is maltose made from?

  Maltose is made from two alpha glucose monosaccharides joined together.
• What is sucrose made from?

  Sucrose is made from glucose and fructose joined together.
• What is the structure of starch?

  Starch is a polysaccharide made from many alpha glucose monomers joined together.
• What is the structure of glycogen?

  Glycogen is similar to starch but is shorter and more branched, found in animal cells.
• What is cellulose made from?

  Cellulose is made from long chains of beta glucose monomers.
• What are reducing sugars and how can they be tested?

  • Reducing sugars include monosaccharides and some disaccharides.
  • Test with Benedict's test: mix sugar solution with Benedict's solution and heat.
  • Positive result: brick red color; negative result: blue color.
• What is the procedure for testing non-reducing sugars?

  Non-reducing sugars must be hydrolyzed to monosaccharides before testing with Benedict's test.
• What is the iodine test used for?

  • The iodine test is used to test for starch.
  • Add iodine dropwise to the starch solution.
  • Positive result: blue-black color.
• What are triglycerides made of?

  Triglycerides are made up of glycerol and three fatty acids.
• What is the role of lipids in the body?

  Lipids serve as energy stores, insulation, and protection for organs.
• How can lipids be tested?

  Mix the test solution with ethanol, shake, add water, and look for a cloudy solution.
• What is the difference between saturated and unsaturated triglycerides?

  Saturated triglycerides have only single carbon-carbon bonds, while unsaturated triglycerides have one or more double bonds.
• What are phospholipids made of?

  Phospholipids are made of a phosphate group, glycerol, and two fatty acids.