Chapter 2: Chemistry of Life Flashcards
What kinds of particles make up matter?
Atoms, elements, molecules, compounds
What is a compound?
Compounds have molecules with more than one element in them.
What is an element?
An element is a pure substance, composed of only one type of atoms.
What is an energy level?
Orbitals are arranged into energy levels (shells), depending on their distance from the nucleus. The farther an orbital extends from the nucleus, the higher its energy level is. The energy level closest to the nucleus has one orbital, so it can hold two electrons. The next energy level has up to four orbitals, so it can hold eight electrons.
What are the four kinds of atoms that make up the majority of the human body?
oxygen, carbon, hydrogen, and nitrogen
How is an ion formed?
An ionic bond forms between an atom that has only one or two electrons in the outermost level (that would normally hold eight) and an atom that needs only one or two electrons to fill its outer level. The atom with one or two electrons simply “donates” its outer shell electrons to the one that needs one or two.
What is meant by an electrolyte dissociating in water?
Ionic compounds usually dissolve easily in water because water molecules are attracted to ions and wedge between the ions—thus forcing them apart. When this happens, we say the compounds dissociate to form free ions.
What is covalent chemical bonding?
Atoms also may fill their energy levels by sharing electrons rather than donating or receiving them. When atoms share electrons, a covalent bond forms.
Why are hydrogen bonds important?
Hydrogen bonds keep water molecules loosely joined together, giving water a weak gluelike quality that helps hold your body together
How is the charge of an ion indicated in a formula?
The formula of an ion always shows its charge by a “+” or “−” superscript after the chemical symbol. Positive ion: Has more protons than electrons
Negative ion: Has gained electrons
What is an organic compound?
Organic compounds are composed of molecules that contain carbon-carbon (C–C) covalent bonds, carbon-hydrogen (C–H) covalent bonds, or both
What are the chemical characteristics of water?
Although water is an inorganic compound, it is essential to life. Found in and around each cell, water is the most abundant compound in the body. Its slightly gluelike properties help to hold the tissues of the body together.
What is the difference between dehydration synthesis and hydrolysis?
In dehydration synthesis, reactants combine only after water is removed. Dehydration synthesis is a reaction in which water is lost from the reactants. In hydrolysis, water (hydro-) disrupts the bonds in large molecules, breaking them down into smaller molecules (lysis). Hydrolysis is virtually the reverse of dehydration synthesis.
Explain the concept of pH.
A higher pH value indicates a low relative concentration of H+—a base. A lower pH value indicates a higher H+ concentration—an acid.
Does an acid have a low or high pH?
Low pH
Does an base have a low or high pH?
High pH
What is the difference between alkalosis and acidosis?
Acidosis is low blood pH and alkalosis is high blood pH
What prevents alkalosis and acidosis from occurring frequently in the body (there are 3 ways)?
The body can remove excess H+ ions by excreting them in the urine. Another way to remove acid is by increasing the loss of CO2 (an acid) by way of the respiratory system. A third way to adjust the body’s pH is by using buffers—chemicals in the blood that maintain pH.
Which types of organic molecules does monosaccharides form?
Monosaccharides are single carbohydrate units
Which types of organic molecules does fatty acids form?
The fatty acid components can be classified as saturated or unsaturated. Saturated fatty acids tend to be solid at room temperature and are found in butter and lard. Unsaturated fatty acids tend to be liquids and are found in oils such as corn oil and olive oil.
Which types of organic molecules does amino acids form?
Proteins are very large molecules composed of basic units called amino acids.
Which types of organic molecules does nucleotides form?
the basic building blocks of nucleic acids are called nucleotides. Each nucleotide consists of a phosphate unit, a sugar (ribose or deoxyribose), and a nitrogen base.
Why is the structure of protein molecules important?
Functional proteins have shapes that enable them to participate in chemical processes of the body. Functional proteins include some of the hormones, growth factors, cell membrane channels and receptors, and enzymes.
What is the role of DNA in the body?
The sequence of different nucleotides along the DNA double helix is the “master code” for assembling proteins and other nucleic acids.
