Biology Chapter on Proteins and Genetics

Small organic molecules that join together to form a chain called a polymer.

Large molecules composed of three or more monomers, which can be identical or different.

A chemical reaction that joins two molecules together by removing a water molecule.

A chemical reaction that breaks down a large molecule into smaller subunits by adding a water molecule.

A type of biological molecule that contains carbon, hydrogen, and oxygen, often in a 1:2:1 ratio.

A carbohydrate with one sugar molecule, serving as the primary energy source for cells.

A carbohydrate formed by linking two monosaccharides. A short-term energy storage source for plants.

A large carbohydrate polymer consisting of many monosaccharides linked together.

A polysaccharide that provides structural support for plant cell walls, not a nutrient source for humans.

A polysaccharide that forms the exoskeletons of insects and spiders.

A type of chemical bond formed when two atoms share electrons to achieve a stable outer electron shell.

A covalent bond where electrons are shared equally between atoms, resulting in a molecule with no overall charge.

A covalent bond where electrons are shared unequally between atoms due to differing electronegativity, resulting in a molecule with slightly positive and negative regions.

A weak attraction between a slightly positive hydrogen atom of one polar molecule and a slightly negative atom (like oxygen or nitrogen) of another polar molecule.

The tendency of water molecules to stick together due to hydrogen bonding. This property helps form water droplets and creates surface tension.

The tendency of water molecules to stick to other substances due to hydrogen bonding. It's important for capillary action and plant water absorption.

The ability of a substance to dissolve other substances. Water is a great solvent due to its polarity.

A mixture of a solvent and one or more dissolved substances.

Substances that are attracted to water due to their polarity and can dissolve in it.

Substances that are not attracted to water due to their non-polar nature and cannot dissolve in it. Examples include fats and oils.

Biological polymers constructed by linking together smaller units called amino acids, resulting in a diverse range of proteins (over 250,000 different proteins).

The primary building blocks of proteins, each having a unique side chain ('R' group) that determines its properties.

A chemical bond that links amino acids together in a protein chain, formed by removing a water molecule.

The sequence of amino acids in a protein chain, determined by genetic instructions in DNA. It's the protein's basic blueprint.

The arrangement of the protein chain in space, resulting from interactions between amino acids. It determines the protein's function.

A cross between two true-breeding parents that differ in two traits, such as seed color and shape. The offspring of this cross will have a unique combination of traits, allowing Mendel to analyze their inheritance patterns.

The inheritance of one trait does not influence the inheritance of another trait. In other words, alleles for different genes are distributed independently during gamete formation.

The ratio of phenotypes observed in the F2 generation of a dihybrid cross, typically expressed as 9:3:3:1. This demonstrates independent assortment and the different combinations of alleles passed down.

True-breeding plants produce offspring with the same traits as themselves generation after generation because they carry only homozygous alleles for each gene.

The first generation of offspring resulting from a cross between two true-breeding parents. This generation exhibits a dominant phenotype for each trait because they inherit one dominant allele from each parent.

Muscle cells are specialized to store calcium ions, playing a crucial role in muscle contraction. They also have the ability to convert glycogen into glucose for energy and synthesize lipoproteins.

The Golgi apparatus is a stack of flattened, interconnected sacs that modify, sort, and package important molecules within a cell. Like a factory's finishing room, it adds final touches to products before they are packaged and exported.

The endomembrane system is a network of internal membranes within a cell that synthesizes, modifies, and transports proteins for export. It's like a complex highway system for moving cargo within the cell.

Antibodies are proteins produced by white blood cells that help protect the body against infections by binding to foreign invaders. They are synthesized on ribosomes of the rough ER, packaged into vesicles, transported to the Golgi apparatus, and released outside the cell.

Lysosomes are membrane-bound sacs that act as the cell's digestive system, breaking down food particles and cellular debris. They contain enzymes that require an acidic environment to function.

Hydrolysis is a chemical reaction that breaks down large molecules into smaller subunits by adding a water molecule. It's essential in digestion and cellular processes.

Lysosomal enzymes are transported to the Golgi apparatus in vesicles formed from the ER. The Golgi then adds a carbohydrate tag to direct the enzymes into vesicles that travel to the lysosomes.

The acidic environment inside lysosomes is created by pumping hydrogen ions across their membranes. This acidic environment is required for the lysosomal enzymes to function properly.

The sugar-phosphate backbone is the structural framework of a DNA strand, formed by alternating sugar and phosphate groups. It provides a stable support for the attached nitrogenous bases.

Nitrogenous bases are organic molecules that form the 'rungs' of the DNA ladder, attached to the sugar-phosphate backbone. There are four main types: adenine (A), thymine (T), guanine (G), and cytosine (C).

Complementary base pairing occurs when specific nitrogenous bases form hydrogen bonds with each other. Adenine always pairs with thymine (A-T), and guanine always pairs with cytosine (G-C).

The two DNA strands run in opposite directions, creating an antiparallel structure. One strand runs 5' to 3', while the other runs 3' to 5'.

DNA replication is the process by which a cell creates an identical copy of its entire DNA molecule. It's essential for cell division and ensures that each daughter cell receives a complete set of genetic information.

DNA polymerases are enzymes that play a crucial role in DNA replication. They move along the separated DNA strands and add free nucleotides to create new complementary strands, ensuring accurate copying of the genetic code.

After DNA replication, each new double helix consists of one original strand from the parent molecule and one newly synthesized strand. This process maintains genetic continuity across generations.

Free nucleotides, the building blocks of DNA, are synthesized in the cytoplasm and transported into the nucleus, where they are used by DNA polymerases to create new strands during replication.