https://www.khanacademy.org/science/ap-biology/chemistry-of-life/properties-structure-and-function-of-biological-macromolecules/v/introduction-to-carbohydrates 2023-04-04T21:01:09.417661961Z Introduction to carbohydrates A carbohydrate is a type of molecule that contains carbon, hydrogen, and oxygen. Carbohydrates can be simple sugars (monosaccharides) like glucose, or they can be made up of multiple sugar units (polysaccharides) like glycogen. They are important in biology as a source of energy and as structural components in plants. video https://cdn.kastatic.org/googleusercontent/d4DSgNMDHgUbRMtEElZfALYamopcHnjOUDhjw7kBPF6_m96DuOVsamPlkdBfgp2vUXJWvBk9Fr0nYLp1SvThlSFD Introduction to carbohydrates A carbohydrate is a type of molecule that contains carbon, hydrogen, and oxygen. Carbohydrates can be simple sugars (monosaccharides) like glucose, or they can be made up of multiple sugar units (polysaccharides) like glycogen. They are important in biology as a source of energy and as structural components in plants. https://cdn.kastatic.org/ka-youtube-converted/6o4WL5jlpn0.mp4/6o4WL5jlpn0.mp4 268 Biomolecules https://www.khanacademy.org/science/jnv-biology-grade-11-revision-course-full-term/x3ed1e7eacb19007a:week-2/x3ed1e7eacb19007a:untitled-530/e/carbohydrates-class-11-biology 2026-04-07T22:23:57.656416987Z Carbohydrates Practice questions on carbohydrate structure and functions. Moumita Sen exercise https://www.khanacademy.org/science/hs-bio/x230b3ff252126bb6:energy-and-matter-in-biological-systems/x230b3ff252126bb6:biomolecules-and-reactions/v/introduction-to-proteins-and-amino-acids 2023-09-14T11:07:34.466749579Z Introduction to proteins and amino acids Proteins, large biomolecules or macromolecules, play a vital role in almost every biological process. They are made up of chains of amino acids, which are their building blocks. These chains, known as polypeptides, can form complex shapes, contributing to the diverse functions of proteins. Proteins can provide structure, facilitate muscle contraction, catalyze reactions as enzymes, and participate in immune response and signaling. Sal Khan video https://cdn.kastatic.org/ka_thumbnails_cache/7d140eef-7cac-45a0-9370-f705e69d9d10_1280_720_base.png Introduction to proteins and amino acids Proteins, large biomolecules or macromolecules, play a vital role in almost every biological process. They are made up of chains of amino acids, which are their building blocks. These chains, known as polypeptides, can form complex shapes, contributing to the diverse functions of proteins. Proteins can provide structure, facilitate muscle contraction, catalyze reactions as enzymes, and participate in immune response and signaling. https://cdn.kastatic.org/ka-youtube-converted/78QUeXVKiJ4.mp4/78QUeXVKiJ4.mp4 353 Biomolecules https://www.khanacademy.org/science/ap-biology/chemistry-of-life/properties-structure-and-function-of-biological-macromolecules/v/overview-of-protein-structure 2021-03-18T10:33:22Z Overview of protein structure Primary, secondary, tertiary and quaternary protein structure. Beta pleated sheets and alpha helices. video https://cdn.kastatic.org/googleusercontent/UbkThjoOiDiecZh69T1rBXQPNKHCs6-M6Ypbkwo3sGFGT56yYDBRb3ATwL9MIYIDZF7em5M91F7kd0IG6e_Pc8SQDg Overview of protein structure Primary, secondary, tertiary and quaternary protein structure. Beta pleated sheets and alpha helices. https://cdn.kastatic.org/ka-youtube-converted/MODnIkQvyz0.mp4/MODnIkQvyz0.mp4 598 Biomolecules https://www.khanacademy.org/science/revision-term-1-ka-biology-grade-11/x1474e0ca4285b2f5:week-3/x1474e0ca4285b2f5:biomolecules/e/proteins 2025-01-28T15:11:19.108941038Z Proteins Test your knowledge on proteins! Ashley exercise https://www.khanacademy.org/science/biology/macromolecules/lipids/v/lipid-overview 2021-03-18T10:33:23Z Lipid overview Types of lipids including fats, waxes, steroids and phospholipids. video https://cdn.kastatic.org/googleusercontent/HXt80w3Mj9aNALsHLHWDoGYqYBd-CAZIb03XpJWMlz_rcAb_1Cboop2ecNdJlZzVDGgnkWZF6y1DGs4lD2Zd3GOe Lipid overview Types of lipids including fats, waxes, steroids and phospholipids. https://cdn.kastatic.org/ka-youtube-converted/Ezp8F7XJHWE.mp4/Ezp8F7XJHWE.mp4 691 Biomolecules https://www.khanacademy.org/science/revision-term-1-ka-biology-grade-11/x1474e0ca4285b2f5:week-3/x1474e0ca4285b2f5:biomolecules/e/lipids 2025-01-28T15:11:19.108941038Z Lipids Test your knowledge on lipids! Ashley exercise https://www.khanacademy.org/science/ap-biology/chemistry-of-life/nucleic-acids-ap/v/antiparallel-structure-of-dna-strands 2023-12-04T19:02:25.924542584Z Antiparallel structure of DNA strands DNA structure consists of two strands, each with a backbone of alternating phosphate and sugar groups. These strands are linked by complementary nitrogenous bases, forming a ladder-like structure. The strands are antiparallel, meaning they run in opposite directions, which is crucial for DNA replication. Sal Khan video https://cdn.kastatic.org/googleusercontent/jlVOYhrBGzFF4uavk6HLPEFezcJ4JuLlY5qyQV1xEBLQZkR_bUVOk-7iIDFFKzmKmfe1iWYRUsI8ZF4LX2aIjL_r Antiparallel structure of DNA strands DNA structure consists of two strands, each with a backbone of alternating phosphate and sugar groups. These strands are linked by complementary nitrogenous bases, forming a ladder-like structure. The strands are antiparallel, meaning they run in opposite directions, which is crucial for DNA replication. https://cdn.kastatic.org/ka-youtube-converted/0CQ5ls3Uc2Q.mp4/0CQ5ls3Uc2Q.mp4 597 Biomolecules https://www.khanacademy.org/science/revision-term-1-ka-biology-grade-11/x1474e0ca4285b2f5:week-3/x1474e0ca4285b2f5:biomolecules/e/dna-structure 2026-04-08T00:36:09.500768563Z DNA structure Questions to practice DNA structure Moumita exercise https://www.khanacademy.org/science/jnv-biology-grade-11-revision-course-full-term/x3ed1e7eacb19007a:week-2/x3ed1e7eacb19007a:untitled-530/e/identifying-the-nature-of-bond-linking-the-monomers-and-the-process-involved 2026-04-08T01:15:04.085520103Z Identifying the nature of bond linking the monomers and the process involved. Let's solve some problems to better understand how the monomers are linked in a polymer and the process involved during that linkage. Aanchal Arora exercise https://www.khanacademy.org/science/ap-biology/cellular-energetics/cellular-energy/v/introduction-to-metabolism-anabolism-and-catabolism 2023-09-14T11:07:34.466749579Z Introduction to metabolism: Anabolism and catabolism Metabolism refers to the set of chemical reactions that occur within living organisms to maintain life. Anabolism is the process of building up larger, more complex molecules from smaller ones. This process requires energy. Catabolism is the process of breaking down larger molecules into smaller ones. This process releases energy that can be used by the organism. Sal Khan video https://cdn.kastatic.org/googleusercontent/VNFBI37HgDDpyj4iio_9O3umRKSzX7l83FTouaKQ9JeEjiPz0aHzWbmVKHjOV3Ju7sVFMsnOAhECbPumXdtHBknurA Introduction to metabolism: Anabolism and catabolism Metabolism refers to the set of chemical reactions that occur within living organisms to maintain life. Anabolism is the process of building up larger, more complex molecules from smaller ones. This process requires energy. Catabolism is the process of breaking down larger molecules into smaller ones. This process releases energy that can be used by the organism. https://cdn.kastatic.org/ka-youtube-converted/KwNe9x0eChs.mp4/KwNe9x0eChs.mp4 607 Biomolecules https://www.khanacademy.org/science/revision-term-1-ka-biology-grade-11/x1474e0ca4285b2f5:week-3/x1474e0ca4285b2f5:biomolecules/e/metabolism-class-11-biology 2026-04-08T01:15:04.085520103Z Metabolism Practice questions on catabolism, anabolism, and ATP Moumita Sen exercise https://www.khanacademy.org/science/exam-preparation-class-11th-biology/x0c1a8c25d3e07544:week-2/x0c1a8c25d3e07544:bimolecules/v/classification-of-enzymes 2023-01-26T10:21:56.90843157Z Classification of enzymes How are enzymes classified? Khadijatul Qubra video https://cdn.kastatic.org/googleusercontent/ZCdwTudJg6e6n-P2gsaUborP4izvMsGo71pvEVlX9dNYWcLXcP7VHkWpn2grt4TUP1KoJLQP9NswyHBuBLSFTBw Classification of enzymes How are enzymes classified? https://cdn.kastatic.org/ka-youtube-converted/8NQKEaS9Zl8.mp4/8NQKEaS9Zl8.mp4 781 Biomolecules https://www.khanacademy.org/science/jnv-biology-grade-11-revision-course-full-term/x3ed1e7eacb19007a:week-2/x3ed1e7eacb19007a:untitled-530/e/enzymes-class-11-biology 2026-04-08T00:16:02.937952483Z Enzymes Practice questions on how enzymes work. Moumita Sen exercise https://www.khanacademy.org/science/biology/energy-and-enzymes/enzyme-regulation/v/enzyme-cofactors-and-coenzymes 2021-03-18T10:33:23Z Enzyme cofactors and coenzymes The cofactors and coenzymes (organic cofactors) that help enzymes catalyze reactions. video https://cdn.kastatic.org/googleusercontent/KACsFdJo65fx1rPaiFqdBhF1fFHvmKP-6U7kojttfRlFvgUf-bh3kikkGXh3ho6j9tyrqJpOdktudyDRA1dJWeob Enzyme cofactors and coenzymes The cofactors and coenzymes (organic cofactors) that help enzymes catalyze reactions. https://cdn.kastatic.org/ka-youtube-converted/jYR0RlMft8Y.mp4/jYR0RlMft8Y.mp4 599 Biomolecules https://www.khanacademy.org/science/jnv-biology-grade-11-revision-course-full-term/x3ed1e7eacb19007a:week-2/x3ed1e7eacb19007a:untitled-530/e/enzyme-regulation-and-inhibition 2023-05-16T11:42:45.366417523Z Enzyme regulation and inhibition Test your knowledge on enzyme regulation and inhibition! Ashley exercise