Protein Structure and Function

Carbohydrates

• Oligosaccharides consist of 3 to 100 monosaccharides.
• Cellulose is the most common polysaccharide found in plant cell walls.
• Glycogen is the stored form of glucose in the body.

Glycoproteins

• Glycoproteins are molecules composed of carbohydrates and proteins.
• The blood type AB refers to a combination of glycoproteins on red blood cells.
• Surgical thread is commonly made from cellulose due to its flexibility and biodegradability.
• Glycoproteins function in cell recognition, signaling, and immune responses.

Proteins

• Regulatory proteins control essential activities within cells.
• Amino acids are distinguished from one another by their unique R groups/side chains.
• Dehydration synthesis is the reaction that connects amino acids to form peptide bonds.
• The sequence of amino acids determines all subsequent structural levels of a polypeptide chain.
• Hydrogen bonds are responsible for secondary structural shapes in polypeptides.
• Chains with fewer than 50 amino acids are referred to as peptides.
• A tripeptide consists of three linked amino acids.
• A polypeptide chain is considered a protein when it achieves a functional structure, usually over 50 amino acids in length.
• Insulin regulates blood sugar levels by promoting glucose uptake in cells.
• The primary function of proteins includes catalyzing biochemical reactions and providing structure.
• The tertiary structure of a protein involves the overall three-dimensional folding, influenced by interactions between R groups.
• Proteins can become denatured due to extreme temperature or pH changes, disrupting their structure and function.

Nucleic Acids

• The quaternary structure of a protein arises from interactions between multiple polypeptide chains.
• Uracil is the nitrogenous base found in RNA but not in DNA.
• The primary difference between DNA and RNA at the sugar level is the presence of ribose in RNA and deoxyribose in DNA.

Lipids

• 'Loss of function' in proteins can most likely occur due to denaturation.
• 'Quaternary Structure' refers to the shape arising from the interactions between multiple protein subunits.
• The main function of DNA is to store and transmit genetic information.
• Adenine, thymine, cytosine, and guanine are nitrogenous bases present in DNA but not in RNA.
• Hydrophobic interactions and van der Waals forces are responsible for the hydrophobic nature of lipids.
• Triglycerides belong to the lipid group known as fats or oils.
• The backbone of a triglyceride molecule consists of glycerol.
• Lipids are produced in cells through metabolic pathways involving fatty acid synthesis.
• Unhealthy foods are typically characterized by high levels of saturated fats and trans fats.
• Saturated fatty acids are defined by having the maximum number of hydrogen atoms and no double bonds in their carbon chains.
• Unsaturated fatty acids are generally liquid at room temperature due to their double bonds causing kinks.
• Cholesterol is considered a key component of animal cell membranes, providing fluidity and stability.
• Saturated fats contribute to increasing cholesterol levels by promoting the formation of low-density lipoprotein (LDL).
• Waxes are classified as lipids that combine with alcohols or hydrocarbons, forming a stiff, water-repellent material.
• The main difference between saturated and unsaturated fatty acids lies in the presence of double bonds in unsaturated fats.
• Steroids differ from waxes in structure and function; steroids are four fused carbon rings, while waxes are long-chain fatty acids.
• An unhealthy diet can contribute to high cholesterol levels by increasing saturated and trans fat intake.
• Monosaccharides are simple sugars, while polysaccharides are complex carbohydrates composed of many sugar units.

Learn about the different levels of protein structure, including primary, secondary, tertiary, and quaternary structures, and how they influence protein function. Explore the concept of denaturation and its impact on protein activity.