A&P one: chapter 2

Matter

"Stuff" of universe Anything that takes up space and has mass Mass doesn't vary/ weight varies with gravity

dehydration synthesis

2 monomers (OH and HO) are joined by removal of OH in one and H in the other (H2O)

Explain why CH 4 is one of the most common molecules found in nature. Are the bonds between the atoms ionic or covalent?

A carbon atom has four electrons in its valence shell. According to the octet rule, it will readily participate in chemical reactions that result in its valence shell having eight electrons. Hydrogen, with one electron, will complete its valence shell with two. Electron sharing between an atom of carbon and four atoms of hydrogen meets the requirements of all atoms. The bonds are covalent because the electrons are shared: although hydrogen often participates in ionic bonds, carbon does not because it is highly unlikely to donate or accept four electrons.

properties of water

Accounts for 2/3 of our body weight, most important inorganic compound High heat capacity universal solvent Reactivity (hydrolysis & dehydration synthesis)

what are proteins made of?

Amino acids Peptide bonds

electrolytes

Chemicals that dissolve in water & are capable of conducting an electrical current

trans fats

Common in margarines, baked goods, fried foods, & most snacks Oils that have been solidified by adding H+ atoms at the site of carbon double bonds Raises your LDL ("bad") cholesterol and lowers your HDL ("good") cholesterol Likely to spoil, so foods made with it have a longer shelf life

disaccarides

Composed of monosaccharide building blocks Formation is via dehydration synthesis Broken down via hydrolysis Too large to pass through cell membranes

Compound

Compound -two or more different atoms combined Ex. Glucose (C6H12O6), Methane (CH4), Carbon dioxide (CO2)

Cohesion

In water- surface tension

lipids

Insoluble in water, dissolve in alcohols Contain carbon, hydrogen, and oxygen Carbon to hydrogen ration is 1:2 Form essential structural elements of all cells Energy reserves Insulation Protection Form hormones

Any metal bound to a non metal is a what?

Ionic compound

AB + CD → AD + BE Is this a legitimate example of an exchange reaction? Why or why not?

It is not. An exchange reaction might be AB + CD → AC + BD or AB + CD → AD + BC . In all chemical reactions, including exchange reactions, the components of the reactants are identical to the components of the products. A component present among the reactants cannot disappear, nor can a component not present in the reactants suddenly appear in the products.

Two forms of energy

Kinetic and potential

polysaccarides

Larger, more complex carbohydrates linked by dehydration synthesis Cellulose (fiber) Starches Glycogen

The pH of lemon juice is 2, and the pH of orange juice is 4. Which of these is more acidic, and by how much? What does this mean?

Lemon juice is one hundred times more acidic than orange juice. This means that lemon juice has a one hundred-fold greater concentration of hydrogen ions.

During a party, Eli loses a bet and is forced to drink a bottle of lemon juice. Not long thereafter, he begins complaining of having difficulty breathing, and his friends take him to the local emergency room. There, he is given an intravenous solution of bicarbonate. Why?

Lemon juice, like any acid, releases hydrogen ions in solution. As excessive H + enters the digestive tract and is absorbed into blood, Eli's blood pH falls below 7.35. Recall that bicarbonate is a buffer, a weak base that accepts hydrogen ions. By administering bicarbonate intravenously, the emergency department physician helps raise Eli's blood pH back toward neutral.

If the disaccharide maltose is formed from two glucose monosaccharides, which are hexose sugars, how many atoms of carbon, hydrogen, and oxygen does maltose contain and why?

Maltose contains 12 atoms of carbon, but only 22 atoms of hydrogen and 11 atoms of oxygen, because a molecule of water is removed during its formation via dehydration synthesis.

Molecules

Molecule - 2 or more atoms of the same atom held together Ex. O2, H2

exchange reaction

Molecules Broken off and traded

cation examples

Na+, K+

Anions

Negative charge

Oxygen, whose atomic number is eight, has three stable isotopes: 16 O, 17 O, and 18 O. Explain what this means in terms of the number of protons and neutrons.

Oxygen has eight protons. In its most abundant stable form, it has eight neutrons, too, for a mass number of 16. In contrast, 17 O has nine neutrons, and 18 O has 10 neutrons.

phospholipids

Polar head(hydrophilic) Non-polar tail(hydrophobic) Cell membrane component

Cations

Positive charge

What subatomic particles are in atoms

Protons (p+) Neutrons (n) Electrons (e-)

When you do a load of laundry, why do you not just drop a bar of soap into the washing machine? In other words, why is laundry detergent sold as a liquid or powder?

Recall that the greater the surface area of the reactants, the more quickly and easily they will interact. It takes energy to separate particles of a substance. Powder and liquid laundry detergents, with relatively more surface area per unit, can quickly dissolve into their reactive components when added to the water.

monosaccarides

Simple sugars: Glucose Fructose Galactose

atom

Smallest units of matter

Energy

The capacity to do work or to put matter in motion

The most abundant elements in the foods and beverages you consume are oxygen, carbon, hydrogen, and nitrogen. Why might having these elements in consumables be useful?

These four elements—oxygen, carbon, hydrogen, and nitrogen—together make up more than 95 percent of the mass of the human body, and the body cannot make elements, so it is helpful to have them in consumables.

denaturization

Unfolding of tertiary structure Caused by changes in temperature or pH May be reversible or irreversible

In a hurry one day, you merely rinse your lunch dishes with water. As you are drying your salad bowl, you notice that it still has an oily film. Why was the water alone not effective in cleaning the bowl?

Water is a polar molecule. It has a region of weakly positive charge and a region of weakly negative charge. These regions are attracted to ions as well as to other polar molecules. Oils are nonpolar, and are repelled by water.

hydrogen bonds

Weakest of the three bonds Attraction of oppositely charged parts of a molecule

transport proteins

assist with moving insoluble items

suspension

heterogeneous mixture; suspended particles that settle out: ex) blood, mud

contractile protein

movement/expansion

carbs

An important source of energy Includes sugars & starches Provide readily available source of cellular fuel

solution

a homogeneous mixture; clear

potential energy

stored energy that results from the position or shape of an object

Once dietary fats are digested and absorbed, why can they not be released directly into the bloodstream?

All lipids are hydrophobic and unable to dissolve in the watery environment of blood. They are packaged into lipoproteins, whose outer protein envelope enables them to transport fats in the bloodstream.

acid

An acid is a solute that releases hydrogen ions (H+) in solution makes solutions acidic

Atomic number is?

Atomic number = # of protons (also # of electrons)

Atomic weight

Average of the mass numbers of all isotopes

ionic bonds

Bond between ions (carry a charge)

isotopes

Atom with a differing number of neutrons than is usually found

non- polar covalent bonds

Do not dissolve in water Fat-soluble Easily diffuse through cell membranes

Atomic mass

Atomic mass = protons + neutrons

buffering proteins

prevent changes in pH

what can influence chemical reactions?

temperature concentration particle size Enzymes

protiens

Contain carbon, hydrogen, oxygen, & nitrogen Variety of functions in the bod

elements

Elements - fundamental substances that make up all matter Ex. Hydrogen (H), Helium (He), Oxygen (O), Carbon (C), etc...

Could two atoms of oxygen engage in ionic bonding? Why or why not?

Identical atoms have identical electronegativity and cannot form ionic bonds. Oxygen, for example, has six electrons in its valence shell. Neither donating nor accepting the valence shell electrons of the other will result in the oxygen atoms completing their valence shells. Two atoms of the same element always form covalent bonds.

Magnesium is an important element in the human body, especially in bones. Magnesium's atomic number is 12. Is it stable or reactive? Why? If it were to react with another atom, would it be more likely to accept or to donate one or more electrons?

Magnesium's 12 electrons are distributed as follows: two in the first shell, eight in the second shell, and two in its valence shell. According to the octet rule, magnesium is unstable (reactive) because its valence shell has just two electrons. It is therefore likely to participate in chemical reactions in which it donates two electrons.

polar covalent bonds

One atom is "greedier" than the other Dissolve in water (water-soluble) Do not freely diffuse through cell membrane

fatty acids

Saturated Fat (animal fat)= solid at room temperature, only single covalent bonds between carbons Unsaturated Fat (plant fat)= liquid at room temperature, one or more double covalent bonds Monounsaturated- single double covalent bond Polyunsaturated - many double covalent bonds

ATP

Source of energy for cells Transport of substances Anabolic reactions

how do you transport non-polar compounds

Surround non-polar with polar

base

a solute that takes up hydrogen ions from a solution makes solutions basic

what does an organic compound contain?

both carbon and hydrogen; inorganic do not contain both

decomposition reaction

broken from large molecules to smaller less complex molecules

kinetic energy

energy of motion

colloid

homogeneous mixture; particles scatter but do not settle: ex) jell-o, milk

what does water dissolve?

ionic compounds Polar covalent bonds

Ribonucleic acid (RNA)

manifest the genetic code as protein

hydrolysis

opposite of dehydration synthesis, water added to separate monomers

pH

pH is a measure of the relative acidity of a solution. Pure water has a pH of 7 "power of hydrogen" pH of 7 is neutral: H+ = OH- pH below 7 is acidic: H+ > OH- pH above 7 is basic: OH- > H+ The scale is logarithmic, 10 times for each #

what is pH regulated by?

pH is regulated by buffers. A buffer can neutralize small amounts of acids or bases in body fluids.

enzymes

proteins that act as biological catalysts They regulate & speed up biochemical reactions increase the rate of a reaction

synthesis reaction

smaller particles bonded to form larger more complex molecules

Deoxyribonucleic acid (DNA)

stores genetic information.