Biology (Black, LU#1)

• Lipids are not true macromolecules because they are not defined by monomers but by their chemical nature
• Carbonyl functional groups are polar and can be oxidized to form carboxylic acids
• Sulfhydryl groups are important because they can create disulfide bonds
• Forming a polymer requires a condensation or dehydration reaction
• Breaking down a polymer requires a hydrolysis reaction
• There are 20 types of amino acids
• The polypeptide monomer is amino acids
• Polysaccharides (also known as carbohydrates) are polymers of monosaccharides
• Nucleic acid polymers are comprised of nucleotide monomers
• An amino acid is comprised of a carboxylic acid group, amine group, and an R-group
• The four types of R-groups/side chains for amino acids are acidic, basic, polar uncharged, and nonpolar
• Amino acids are linked together through covalent peptide bonds, linking the carboxylic acid of one to the amine group of the other.
• The amino group of a polypeptide is called an N-terminal and the carboxylic acid tail is called the C-terminal
• Chaperone proteins prevent proteins from folding incorrectly and help them to fold correctly
• The prion protein that induces improper folding of other proteins
• A denatured protein loses its tertiary and second structure and function, but not its primary structure
• The RNA world hypothesis is the idea that the first life on Earth was RNA-based due to its ability to self-replicate
• Nucleotides are made of a nitrogenous base, a sugar, and a phosphate group
• The primary structure of nucleic acids is the sequence of nucleotides
• Nucleotides link together through a phosphodiester linkage from the 5-carbon sugar to the phosphate group
• Purine nucleotides (adenine and guanine) are bigger than pyrimidines (uracil and thymine and cytosine)
• Ribose has an OH at carbon #2 while deoxyribose does not have this OH which causes RNA to be more chemically reactive
• DNA contains two strands held together by hydrogen bonds between complementary bases
• In DNA, adenine always pairs with thymine via 2 H-bonds and cytosine always pairs with guanine via 3 H-bonds
• Nucleotides are added to the 3’ end of DNA and RNA
• The nitrogenous bases of DNA is nonpolar which causes the structure to twist
• Monosaccharides covalently bond through glycosidic linkages to make polysaccharides
• Carbohydrates can help with cellular identification
• Energy is stored in hydrocarbon bonds because of the large amount of potential energy
• The orientation of hydroxyl groups in carbohydrates dictates alpha versus beta linkages
• Chitin has extra structural support due to the presence of hydrogen bonds between an extra prosthetic group. It is present in insect exoskeletons
• Peptidoglycan is a polysaccharide comprised of glucose with an amino acid allowing it to form peptide bonds. This is the main component of the bacterial cell wall
• The plasma membrane is comprised of phospholipids and proteins
• Saturated fatty acids are solid at room temperature because they are only comprised of single carbon-carbon bonds while unsaturated fatty acids are liquid at room temperature because they are comprised of double carbon-carbon bonds causing kinks in the structure
• Lipid bilayers form spontaneously due to the nonpolar nature of the phospholipids
• Phospholipids can compensate for temperature changes by changing the amount of saturated or unsaturated tails. Saturated tails are created in response to cold temperatures and unsaturated tails are created in response to warm temperatures.
• The sperm/egg experiment exposed sperm to protein and carbohydrate components and then measured the egg attachment inhibition to confirm that sperm recognize the carbohydrates on eggs
• Fats have three fatty acid tails while phospholipids only have two fatty acid tails and a negative phosphate group
• The 5’ end of DNA and RNA is the phosphate group and the 3’ end is the sugar hydroxyl
• Ribozymes are RNA molecules that can catalyze reactions