Module 1 Flashcards
What governs the properties of life?
Matter and energy
All organisms are made up of matter and require energy to sustain life.
How do organisms obtain matter?
From other organisms and the environment
Matter moves in a cycle, with the same atoms used and reused.
What is the source of energy used by organisms?
The sun or chemical compounds
Energy cannot be reused by organisms.
What is the fundamental unit of matter?
The atom
Atoms consist of protons, neutrons, and electrons.
What does the atomic number represent?
The number of protons an element contains
It determines the identity of the element.
What is the atomic mass?
The number of protons and neutrons an element contains
It reflects the mass of the atom.
What are isotopes?
Elements with the same number of protons but different numbers of neutrons
Isotopes have similar chemical properties but differ in mass.
Where do electrons occupy in an atom?
Energy shells or levels around the nucleus
Electrons move in these energy levels.
What organizes all of the elements and describes their properties?
The periodic table
The periodic table arranges elements based on their atomic number and properties.
What are the electrons in an atom’s outermost energy shell called?
Valence electrons
Valence electrons determine an atom’s ability to bond with other atoms.
What type of bond arises when two elements share one or more pairs of electrons?
Covalent bonds
Covalent bonds can involve single, double, or triple pairs of shared electrons.
Covalent bonds can be categorized into which two types?
Nonpolar and polar
Nonpolar covalent bonds share electrons equally, while polar covalent bonds share them unequally.
What type of bond results from the attraction of oppositely charged ions?
Ionic bonds
Ionic bonds typically form between metals and nonmetals.
What do chemical reactions involve?
The breaking and forming of chemical bonds
This process results in the formation of new molecules.
What is the backbone of organic molecules?
Carbon
Carbon’s unique properties allow it to form a wide variety of organic compounds.
How many covalent bonds can carbon form?
Four covalent bonds
Carbon’s tetravalency allows it to bond with many different elements.
What allows a diversity of molecules to be formed?
Carbon’s bonding
Carbon can form chains and rings, contributing to molecular diversity.
What are the four major classes of organic molecules?
Proteins, nucleic acids, carbohydrates, and lipids
Each class has distinct roles and structures in biological systems.
What role do proteins play in cells?
Structure and catalysis of chemical reactions
Proteins can act as enzymes, speeding up biochemical processes.
What are proteins made up of?
Proteins are made up of subunits called amino acids.
Amino acids are the building blocks of proteins.
What role do nucleic acids play?
Nucleic acids are information molecules and the molecules of heredity.
They are essential for storing and transmitting genetic information.
What are nucleic acids made up of?
Nucleic acids are made up of subunits called nucleotides.
Nucleotides consist of a sugar, a phosphate group, and a nitrogenous base.
What is the primary function of carbohydrates?
Carbohydrates, or sugars, store energy and make up the external layer of some types of cells.
They play a critical role in energy storage and cellular structure.
What are carbohydrates made up of?
Carbohydrates are made up of simple sugars, called monosaccharides.
Monosaccharides are the simplest form of carbohydrates.
What are lipids?
Lipids are hydrophobic molecules that make up the cell membrane, store energy, and act as chemical messengers.
They include fats, oils, and hormones.
