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What are the major functional groups present in organic compounds?
What are the major functional groups present in organic compounds?
Hydroxyl, carboxyl, amino, phosphate, and methyl groups.
Carbon dioxide is considered an organic molecule.
Carbon dioxide is considered an organic molecule.
False
What is the primary composition of carbohydrates?
What is the primary composition of carbohydrates?
What molecule is released when two subunits join to form a macromolecule?
What molecule is released when two subunits join to form a macromolecule?
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What ratio do the atoms in carbohydrates typically maintain?
What ratio do the atoms in carbohydrates typically maintain?
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What is the simplest form of carbohydrates?
What is the simplest form of carbohydrates?
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____ are two monosaccharides linked by dehydration synthesis.
____ are two monosaccharides linked by dehydration synthesis.
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What is glycogen used for in animals?
What is glycogen used for in animals?
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Chitin is found in which of the following?
Chitin is found in which of the following?
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What is cellulose primarily used for in plants?
What is cellulose primarily used for in plants?
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What type of bond links amino acids together in proteins?
What type of bond links amino acids together in proteins?
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What structure do proteins achieve through interactions of their R groups?
What structure do proteins achieve through interactions of their R groups?
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What determines the properties of an amino acid?
What determines the properties of an amino acid?
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Which level of protein structure involves multiple polypeptide subunits?
Which level of protein structure involves multiple polypeptide subunits?
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Study Notes
Carbon - The Basis of Life
- Carbon has four valence electrons in its outer orbital, allowing it to form four covalent bonds.
- Carbon bonds with oxygen, hydrogen, nitrogen, sulfur, phosphorous, and other carbon atoms to form complex biomolecules.
Organic Molecules
- Organic molecules contain carbon skeletons held together by covalent bonds (C-C and C-H).
Synthesis of Biological Molecules
- In dehydration synthesis, a water molecule is released to join two subunits, forming a macromolecule.
- This process is also known as condensation.
- In hydrolysis, a water molecule is required to break down macromolecules into smaller subunits.
Functional Groups of Biological Molecules
- Functional groups are specific arrangements of atoms in organic molecules that give them unique chemical properties.
- Common functional groups include hydroxyl, carbonyl, carboxyl, amino, and phosphate groups.
Carbohydrates
- Composed of carbon, hydrogen, and oxygen atoms in a ratio of 1:2:1, represented by the formula (CH2O)n.
Principle Subtypes of Carbonhydrates
- Monosaccharides are simple sugars and are the subunits of polysaccharides.
- Disaccharides are formed when two monosaccharides are linked by dehydration synthesis.
- Polysaccharides are long chains of repeating monosaccharide units, usually glucose.
Functions of Carbohydrates
-
Energy storage:
- Glycogen in animals
- Starch in plants
-
Structural support:
- Cellulose in plants
- Chitin in the shells of crustaceans, exoskeletons of insects, and the cell walls of fungi
-
Biologically active molecules:
- Hyaluronic acid in synovial fluid for lubrication
- Heparin in blood as an anticoagulant
Monosaccharides
- Consist of 3-7 carbon atoms.
- Most carbon atoms are attached to hydrogen and hydroxyl groups.
- Water-soluble and form a ring structure.
- Provide immediate energy.
Disaccharides
- Formed when two monosaccharides are linked by dehydration synthesis.
- A glycosidic bond is formed between the anomeric carbon of one monosaccharide and a hydroxyl oxygen of another.
- Act as short-term energy storage in plants.
Polysaccharides
- Long chains of repeating monosaccharides, usually glucose.
- Provide energy storage (glycogen in animals, starch in plants), and structural support (cellulose in plants, chitin in shells and exoskeletons).
Starch
- Composed of α-glucose molecules:
- Amylose with α-1,4 linkages
- Amylopectin with α-1,6 linkages
- Water-insoluble and stored as granules in plastids.
Glycogen
- Similar to starch but more extensively branched with more α-1,6 linkages.
- More soluble in water than starch.
- Stored in liver and muscle tissues.
Cellulose
- Made of β-glucose molecules with β-1,4 linkages cross-linked by hydrogen bonds.
- Water-insoluble.
- Found in cell walls of plants.
Chitin
- Made of β-glucose molecules with β-1,4 linkages and a nitrogen-containing functional group at carbon 2.
- Gives strength to the exoskeletons of crustaceans and insects and the cell walls of fungi.
Physical and Biological Properties of Polysaccharides
- The physical and biological properties of polysaccharides depend on the arrangement of their subunits.
- Alpha form: Less stable due to steric hindrance caused by the orientation of hydroxyl groups, but is readily broken down by enzymes.
- Beta form: More stable and less reactive due to the orientation of hydroxyl groups, but is not easily broken down by enzymes.
Proteins
- Composed of one or more chains of amino acid residues joined together by peptide bonds.
Amino Acid Structure
- Amino acids are the building blocks of proteins.
- They consist of a central carbon atom bonded to:
- An amino group (-NH2)
- A carboxyl group (-COOH)
- A hydrogen atom (-H)
- A variable side chain (R group)
Amino Acid R Groups
- The R group determines the properties of an amino acid:
- Size
- Water solubility
- Electrical charge/pH
- Formation of disulfide bridges (cysteine)
Dehydration Synthesis of Proteins
- Peptide bonds are formed between the amino group of one amino acid and the carboxyl group of another amino acid through dehydration synthesis.
Polypeptides
- Polypeptides are long chains of amino acids linked by peptide bonds.
Levels of Protein Structure
- Primary structure is the sequence of amino acids in a polypeptide chain.
- Secondary structure arises from interactions between atoms of the backbone, leading to locally folded structures like alpha helices, beta sheets, coils, and turns.
- Tertiary structure is the three-dimensional structure of a polypeptide, formed through interactions between the R groups of the amino acids.
- Quaternary structure occurs in proteins composed of multiple polypeptide subunits.
Bonds Stabilizing Protein Structure
- Protein structure is stabilized by various bonds:
- Hydrogen bonds
- Ionic bonds
- Hydrophobic interactions
- Disulfide bridges
Comparison Between Protein Subtypes
- Proteins have diverse structures and functions depending on their amino acid sequence and folding.
- Examples:
- Keratin (secondary structure)
- Myoglobin (tertiary structure)
- Hemoglobin (quaternary structure)
Foldit
- Foldit is a protein folding game that utilizes citizen science to help scientists understand protein structures.
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Description
Explore the fundamental role of carbon in biological systems through this quiz. Understand how carbon forms covalent bonds and the importance of organic molecules in living organisms. Test your knowledge on the synthesis of biological molecules and the various functional groups that define them.
