Chemistry and Cell Biology Review

Flashcards for review on the major concepts of chemistry, biomolecules, and cellular structure relevant for the upcoming exam.

What does the atomic number represent in an element?

The atomic number is the number of protons in an element.

What determines an element's mass number?

The mass number is determined by the total number of protons and neutrons in the nucleus.

What are the primary elements that make up 96% of matter in organisms?

Hydrogen (H), Carbon (C), Nitrogen (N), and Oxygen (O).

What are isotopes?

Isotopes are different forms of an element with the same number of protons but a different number of neutrons.

What are valence electrons?

Valence electrons are the electrons in the outermost shell of an atom that determine its chemical properties.

What type of bond is formed when electrons are shared between atoms?

Covalent bond.

What characterizes a polar covalent bond?

In a polar covalent bond, electrons are shared unequally between atoms.

What type of bond forms between positively and negatively charged ions?

Ionic bond.

What is required for the formation of a hydrogen bond?

A hydrogen atom covalently bonded to a highly electronegative atom and a lone pair of electrons on another electronegative atom.

What is the difference between hydrophilic and hydrophobic molecules?

Hydrophilic molecules can bond with water ('water-loving'), while hydrophobic molecules cannot bond with water ('water-hating').

What is dehydration synthesis?

Dehydration synthesis is a reaction that joins monomers by removing water and requires energy.

What is hydrolysis?

Hydrolysis is a reaction that breaks down polymers by adding water and releases energy.

What are glycosidic bonds?

Glycosidic bonds are formed by a dehydration reaction between two monosaccharides.

What are the two types of glycosidic bonds and their structures?

Alpha glycosidic bonds form flexible helical structures (starch), while beta glycosidic bonds form straight rigid structures (cellulose).

What is the main function of phospholipids in cells?

Phospholipids are primarily responsible for membrane structure.

What are the four levels of protein structure?

1° Primary, 2° Secondary, 3° Tertiary, and 4° Quaternary.

What is the directionality of nucleic acid synthesis?

Nucleic acids are built in the 5' to 3' direction.

What is the endosymbiont hypothesis?

The endosymbiont hypothesis suggests that mitochondria and chloroplasts evolved from prokaryotic cells and have characteristics like double membranes and their own circular DNA.

What are ribosomes responsible for?

Ribosomes are responsible for protein synthesis.

What differentiates prokaryotic cells from eukaryotic cells?

Prokaryotic cells do not have a nucleus or organelles and are smaller than eukaryotic cells, which have a nucleus and organelles.

What is simple diffusion?

Simple diffusion is the movement of molecules down their concentration gradient without the need for energy.

What is active transport?

Active transport is the movement of molecules against their concentration gradient, requiring energy.