Visual anatomy and physiology by Verna/chapter 2
Chemistry is the science that studies the structure of matter, which is defined as anything that takes up space and has mass.
Have a positive electrical charge
Are electrically neutral, which means they are unchanged.
Are much smaller and about 1/1800th the mass of either protons or neutrons. They bear a negative electrical charge.
Are the smallest stable units of matter.
Three of which are important for understanding the basic chemical properties of matter. (protons, neutrons, electrons)
Atoms can be subdivided into the nucleus and the electron cloud.
The electrons in the atom whirl around the nucleus, creating an electron cloud.
A molecule is formed when atoms interact and produce larger, more complex structures.
Atoms normally contain equal numbers of protons and electrons. The number of protons in an atom is known as the atomic number.
The outermost energy level forms the surface of the atom. Atoms with unfilled energy levels, such as hydrogen and lithium, will react with other atoms, usually in ways that give them full outer energy levels. An atom with a filled outermost energy level is stable and does not readily react with other atoms.
Elements that do not readily participate in chemical processes are said to be inert.
Helium and neo which have filled outermost energy levels, are called inert because their atoms neither react with one another nor combine with atoms of other elements
Elements with unfilled outermost energy levels, such as hydrogen, lithium, or sodium. Because they readily interact or combine with other atoms. In doing so, these atoms achieve stability by gaining, losing, or sharing electrons to fill their outermost energy level.
The loss of electrons from the outer energy level, the result is an atom that is no longer electrically neutral - it now has more protons than electrons. The atom has a net positive charge.
Cation (positive ion)
Atoms achieve stability by filling their outer energy level with electrons obtained from other atoms. This also creates an atom that is no longer electrically neutral- it has more electrons than protons. The atom now has a net negative charge.
Anion (negative ion)
The interactions that stabilize the outer energy levels of atoms often result in the formation of chemical bonds. These bonds hold the participating atoms together once the reaction has ended.
When chemical bonding occurs the result is the creation of new chemical entities called compounds and molecules. A compound is a chemical substance made up of atoms of two or more different elements, regardless of the type of bond joining them.
Chemical bonds created by the electrical attraction between cations (positive ions) and anions (negative ions). This involves the transfer of one or more electrons from an atom that can lose them to achieve stability, to another atom that can gain them to achieve stability.
Some atoms can complete their outer electron shells not by gaining or losing electrons, but by sharing electrons with other atoms.
Two atoms share their electrons to fill their outer energy levels, and the electron pair orbits both nuclei. One electron is contributed by each atom, so this is called a single covalent bond.
Single covalent bond
An oxygen atom has 6 electrons in its outer energy level. By forming a double covalent bond with another oxygen atom, an oxygen molecule is created with a stable outer energy level.
Double covalent bond
In a typical covalent bond, the participating atoms share electrons equally and there is no electrical charge on the molecule. Due to this lack of electrical charge, such molecules are called non polar molecules.
Non polar molecules
In a water molecule, the electron clouds of the hydrogen atoms are distorted because the 8 protons in the oxygen atom exert a much stronger attraction for the electrons than do the single protons of the hydrogen atoms. As a result each hydrogen atom carries a slightly negative charge(-). This creates an asymmetrical polar molecule.
Covalent bonds that produce molecules
Polar covalent bonds
how is it possible for two samples of hydrogen to contain the same number of atoms yet have different weights.
Indicate the maximum number of electrons that can occupy each of the first three electron shells(energy levels) of an atom.
Explain why the atoms of the inert elements do not react with one another or combine with atoms of other elements.
Explain how cations and anions form.
Name and distinguish between the two most common types of chemical bonds.
Describe the kind of bonds that hold the atoms in a water molecule together.
Relate why we can apply the term molecule to the smallest particle
of water but not to that of table salt.
Solid, liquid, gas
Most matter in our environment exist in one of three states.
Maintain their volume and their shape at ordinary temperatures and pressures.
A constant volume but no fixes shape
Neither a constant volume nor a fixed shape. It can be compressed or expanded. Unlike liquids they will fill a container of container of any size.
A solid, liquid, and gas.
The small positive charge on the hydrogen atoms of one polar molecule can be attracted to the negative charges on another polar molecule, and this can change the shapes of the molecules or pull adjacent molecules together. (this is a weak attractive force)
At water surface, the hydrogen bonds between water molecules slow the rate of evaporation and creates this phenomenon surface.
By what means are water molecules attracted to each other.
Cells remain alive and function by controlling chemical reactions. In chemical reactions, new chemical bonds form between atoms, or existing bonds between atoms are broken.
Changes occur as atoms in the reacting substances, or reactants are rearranged to form different substances
The sum of all biochemical processes under way within the human body at any moment; includes anabolism and catabolism.
The movement of an object or a change in the physical structure of matter. In your body this includes; walking running, and also synthesis of molecules and the conversion of liquid water to water vapor (evaporation)
The capacity to perform work; movement or physical change cannot occur unless energy is provided
Motion- energy that can be transferred to another object and perform work.
Stored. Energy that has the potential to do work.
Enables us to describe complex events briefly and precisely.
Decomposition, Synthesis, Exchange
There are three basic types of chemical reaction
A reaction that breaks a molecule into smaller fragments before absorption begans
A reaction assembles smaller molecules into larger molecules. They always involves the formation of new chemical bonds, whether the reactants are atoms or molecules.
reactions involving water is important in the break down of complex molecules in the body.
What does decomposition reaction involve
Collectively, the decomposition reactions of complex molecules within the body's cells and tissues are referred to as (a throwing down)catabolism.
condensation, is the formation of a complex molecule by the removal of a water molecule.
Collectively, the synthesis of new molecules within the body's cells and tissues is know as (a throwing upward) Because it takes energy to create a chemical bond, anabolism is usually considered an "uphill" process.
Parts of the reacting molecules are shuffled around to produce new products.
Distinguish the roles of water in hydrolysis and dehydration synthesis reactions
In cells, glucose, a six carbon molecule, is converted into two three - carbon molecules by a reaction that releases energy. What is the source of the energy?
The amount of energy required to start a reaction
Although many reactions can be activated by changes in temperature or acidity, such changes are deadly to cells. Instead your cells use special proteins called enzymes to perform most of the complex synthesis and decomposition reactions in your body.
Chemical reactions by lowering the activation energy requirements. In doing so,, they make it possible for chemical reactions such as the breakdown of sugars, to proceed under conditions compatible with life.
What does enzymes promote
of substances called catalyst dissolution)compounds that accelerate chemical reactions without themselves being permanently changed or consumed. Enzymes reactions, which are generally reversible, proceed until an equilibrium becomes established.
What class does enzymes belong to?
The complex reactions that support life proceed in a series of interlocking steps, each controlled by a specific enzyme.
Reactions that release energy. This reactions are relatively common in the body. They are responsible for generating the heat that maintains your body temperature.
If more energy is required to begin the reaction than is released as it proceeds.
Essential metabolites that are normally obtained from the diet, which can be broadly categorized as either organic or inorganic.
Always contain carbon and hydrogen as their primary structural ingredients.
Generally do not contain carbon and hydrogen as their primary structural ingredients.
What is an enzyme?
Explain the differences between metabolites and nutrients.
Why are enzymes needed in our cells?
Reduces friction within joints and in body cavities. In our bodies, chemical reactions occur in water. Has a high heat capacity. Changes from solid, to liquid, to gas. It is a solution ( a mixture of 2 or more substances).
In this process, ionic bonds are broken as the individual ions interact with positive or negative poles of polar water molecules.
Ionization or dissociation
A water molecule has positive and negative poles. This polarity is due to the asymmetrical positions of the hydrogen atoms that are attached by polar covalent bonds.
Dissociates as water molecules break the apart. Anions are surrounded by the positive poles of water molecules, and the cation are surrounded by the negative poles of water molecules.
In solutions what do ionic compounds do?
The sheath of water molecules around an ion in a solutions is called?
An organic molecule containing polar covalent bonds.
What do hydration spheres form around?
If the molecule binds water strongly as does glucose it will be carried into solutoin - in other words, it will dissolve. Molecules that interact readily with water moleclues in this way are called?
Soluble inorganic molecules whose ions will conduct an electrical current in a solution.
What are electrolytes?
Dissociation; the break down of a molecule in solution to form ions.
Sodium chloride, potassium chloride, calcium phosphate, sodium bicarbonate, magnesium chloride, sodium hydrogen phosphate, sodium sulfate
Important electrolytes that dissociate in body fluids.
Many organic molecules either lack polar covalent bonds or have very few.
Are said to be nonpolar.
Organic molecules that either lack polar covalent bonds or have very few do not have positive and negative poles
Hydrophobic ( among the most familiar hydrophobic
Molecules that do not readily interact with waterwater are called
A solution containing dispersed proteins or other large particles,( liquid Jell-o)
Contains larger particles that will,if undisturbed, settle out of solution due to gravity.
Hydrogen atoms involved in a chemical bond or participating in a chemical reaction can easily lose its electron to become a
Extremely reactive in solution. In excessive numbers, they will break chemical bonds, change the shapes of complex molcules,and generally disrupt cells and tissue functions. As a result, the concentration of hydrogen ions in body fluids must be regulated precisely
PH (the pH scale ranges from 0 to 14).
What is define as the negative logarithm of the hydrogen ion concentration in moles per liter (mol/L).
7.35 to 7.45
The pH of blood normally ranges from
It can damage cells and tissues by breaking chemical bonds,changing the shapes of proteins, and altering cellular functions.
What does abnormal flucuations in pH do?
An abnormal physiological state caused by low blood pH (below 7.35); a pH below 7 can produce coma.
Results from an abnormally high pH (above 7.45); a blood pH above 7.8 generally causes uncontrollable and sustained skeletal muscle contractions.
A solution with a pH below 7 (contains more hydrogen ions than hydroxide ions.
A solution with a pH of 7 (contains equal numbers of hydrogen and hydroxide).
A pH above 7 is basic. (It has more hydroxide ions than hydrogen ions).
Any solute that dissociates in solution and releases hydrogen ions,thereby lowering the pH.
Is a strong base, in solution it releases sodium ions and hydroxide ions.
What do weak acids and weak bases fail to do?
An ionic compound consisting of any catiion except a hydrogen ion and any anion except a hydroxide ion.
An ion compound that stabilize the pH of a solution by removing or replacing hydrogen ions. (Involves weak acid and its related salt which functions as a weak base.
What does carbohydrates contain
Most important as energy sources that are catabolized rather than stored.
The hexose glucose
The most important metabolic fuel in the body
Always contain the elements carbon and hydrogen, and generally oxygen as well.
Energy source, manufactured in the body and obtained from food; distributed in body fluids.
Monosaccharides (simple sugars) - glucose, fructose
Energy source, sucrose is table sugar, lactose is in milk, and maltose is malt sugar; all must be broken down to monosaccharides before absorption.
Disaccharides (sucrosse, lactose, maltose)
Some molecules have the same molecular formula, in other words, the same types and numbers of atoms, but different strutures
Storage of glucose, glycogen is in animal cells; other starches and cellulose arewithinor around plant cells.