Biochemistry Enzymes, Lipids, and Nucleic Acids

Enzymes are biological catalysts that speed up chemical reactions in living organisms without being consumed in the process.

Enzymes lower the activation energy needed for a reaction to occur, thus accelerating the reaction rate.

The active site is a specific region on an enzyme's surface where the substrate binds.

Enzymes are primarily composed of proteins, though some may require additional components.

The shape of an enzyme's active site determines its specificity for a particular substrate.

Cofactors are non-protein molecules that assist enzymes in their catalytic function.

Oxidoreductases catalyze oxidation-reduction reactions, involving the transfer of electrons or hydrogen atoms.

Competitive inhibitors bind to the active site of an enzyme, blocking the substrate from binding.

Factors like temperature, pH, and substrate concentration influence enzyme activity.

Enzyme saturation occurs when all active sites are occupied by substrate molecules, preventing further increases in activity.

Lipids are a diverse group of organic compounds characterized by their insolubility in water, but solubility in organic solvents.

Lipids play crucial roles in energy storage, cell membrane structure, hormone production, and insulation.

Unsaturated fats contain one or more double bonds between carbon atoms in their fatty acid chains.

Phospholipids are a type of lipid that forms the bilayer structure of cell membranes.

Steroids are lipid-based molecules involved in signaling pathways, regulating many body functions.

A triglyceride consists of three fatty acids bonded to a glycerol molecule.

The hydrophobic nature of lipids is due to their long carbon chains with primarily nonpolar C-H bonds.

Saturated fats have only single bonds between carbon atoms in their fatty acid chains.

Steroids are a major class of lipids, along with triglycerides and phospholipids.

Cholesterol is an essential lipid for cell membrane structure and hormone synthesis.

Nucleic acids are polymers composed of nucleotide monomers.

The backbone of a DNA molecule consists of alternating sugar (deoxyribose) and phosphate groups.

Uracil is a nitrogenous base found in RNA but not in DNA.

The bond linking nucleotides in nucleic acids is called a phosphodiester bond.

DNA carries the genetic information that directs the synthesis of proteins.

Transcription is the process of copying genetic information from DNA into RNA.

tRNA molecules transport specific amino acids to the ribosome during protein synthesis.

Cytosine is a pyrimidine base found in both DNA and RNA.

DNA polymerase is the enzyme responsible for adding nucleotides to a growing DNA strand during replication.

mRNA carries the genetic code from DNA to the ribosome, where protein synthesis occurs.

Hydrogen bonds form between complementary base pairs in DNA, holding the two strands together.

In RNA, adenine pairs with uracil, while guanine pairs with cytosine.

Deoxyribose is the sugar found in DNA.

Thymine is a pyrimidine base found only in DNA.

rRNA is a component of ribosomes, essential for protein synthesis.

Watson and Crick proposed the double helix model of DNA based on experimental data.

The leading strand of DNA is synthesized continuously in the 5' to 3' direction during replication.

A nucleotide is a monomer for nucleic acids, consisting of a sugar, a phosphate group, and a nitrogenous base.

Hydrogen bonds form between complementary base pairs in DNA, stabilizing the double helix structure.

The DNA molecule has a double helix shape, resembling a twisted ladder.

Phosphatases are enzymes that remove phosphate groups from molecules.

Phospholipids form the bilayer structure of cell membranes, creating a barrier between the cell and its environment.

In DNA, adenine (A) pairs with thymine (T), and guanine (G) pairs with cytosine (C).

Light intensity does not directly influence enzyme activity.

Uracil replaces thymine in RNA.

The nitrogenous base in nucleotides contains nitrogen.

Cholesterol is a key lipid for hormone synthesis, including steroid hormones like testosterone and estrogen.

Lipases are enzymes that digest lipids.

DNA replication occurs in the nucleus of eukaryotic cells.

Helicase is the enzyme responsible for unwinding the DNA helix during replication, separating the two strands.