module 1 studyguide atoms, ions and chemical bonds

Atom

Smallest particle still characterizing a chemical element

Cannot be cut into smaller particles, the atoms of modern parlance are composed of subatomic particles: electrons, neutrons, and protons

Electron

Have a negative charge, a size which is so small as to be currently unmeasureable

Proton

Positive charge, and are about 1836 times more massive than electrons

Neutron

No charge, and are the same size as protons.

Both this and protons make up the nucleon (nucleus). Electrons make up the electron cloud surrounding it.

Atomic mass

The sum of the proton and neutrons in an atom is equal to the atomic mass of the atom

Atomic number

The number of protons in an atom is given as its atomic number

ex: carbon has six protons → atomic number is 6

Isotopes

Of an element have nuclei with the same number of protons (the same atomic number) but different numbers of neutrons.

Covalent bond

bond in which one or more pairs of electrons are shared by two atoms

Ionic bond

bond in which one or more electrons from one atom are removed and attached to another atom, resulting in positive and negative ions which attract each other

Hydrogen bond

H, N, O, F

stronger IMF than covalent bond, making it more polar

Acids

Are ionic compounds (a compound with a positive/negative charge) that break apart in water to form a hydrogen ion (H+)

Characteristics:

Taste sour

React strongly with metals

Are dangerous and can burn your skin

ex: vinegar, stomach acid (HCl), citrus fruits

Bases

Are ionic compounds that break apart to form a negatively charged hydroxide ion (OH-) in water.

OH-

Characterisitics:

Taste bitter

Feel slippery

Are very dangerous and can burn your skin

ex: sodium hydroxide (NaOH) and ammonia

Neutralization reaction

When acids and bases are added to each other they react to neutralize each other if an equal number of hydrogen and hydroxide ions are present.

When this occurs, salt and water are formed.

pH

The strength of an acid or base in a solution is measured on a scale.

>7 is base

<7 is acid

7 is neutral

0-14

Galactosemia

An inherited autosomal recessive trait that affects the way the sugar galactose is broken down, due to the lack of the enzyme galactose-1-phosphate uridyl transferase.

In this, galactose builds up and becomes toxic from the body using glucose for energy. In reaction to this build up of galactose, the body makes some abnormal chemicals.

Treatment for galactosemia

restrict galactose and lactose from the diet for life

Signs and symptoms from galactose build up

swollen and inflamed liver

kidney failure

ovarian failure in girls

mental growth

cataracts in the eyes

Functions of proteins

1. Binding, transport and storage - small molecules are often carried by proteins in the physiological setting (for example, the protein hemoglobin is responsible for the transport of oxygen to tissues). Many drug molecules are partially bound to serum albumins in the plasma

2. Molecular switching - conformational changes in response to pH or ligand binding can be used to control cellular processes .

3. Coordinated motion - muscle is mostly protein, and muscle contraction is mediated by the sliding motion of two protein filaments, actin and myosin

4. Structural support - skin and bone are strengthened by the protein collagen

5. Immune protection - antibodies are protein structures that are responsible for reacting with specific foreign substances in the body

6. Generation and transmission of nerve impulses - some amino acids act as neurotransmitters, which transmit electrical signals from one nerve cell to another. In addition, receptors for neurotransmitters, drugs, etc. are protein in nature. An example of this is the acetylcholine receptor, which is a protein structure that is embedded in postsynaptic neurons.

7. Control of growth and differentiation - proteins can be critical to the control of growth, cell differentiation and expression of DNA. For example, many hormones and growth factors that regulate cell function, such as insulin or thyroid stimulating hormone are proteins

If protein and caloric intake are both inadequate, a condition called marasmus occurs.

Marasmus

Form of severe protein-energy malnutrition characterized by energy deficiency. Cachexia.

Presents stoppage of growth, extreme muscle loss, and weakness.

Signs:

dry skin, loose skin folds hanging over the gluti, axillae, etc.

drastic loss of adipose tissue from normal areas of fat deposits like buttocks and thighs

are fretful, irritable, and voraciously hungry

alternate bands of pigmented and depigmented hair or flaky paint appearance of skin due to peeling

Atherosclerosis

A condition in which fatty material collects along the walls of arteries. This fatty material thickens, hardens, and may eventually block the arteries.

Ketone bodies

are three water soluble compounds that are produced as by-products when fatty acids are broken down for energy

they are used as a source of energy in the heart and brain

in the brain, vital source in fasting

name

acetoacetate

name

acetone

name

B-hydroxybutyrate

Ketoacidosis

Too many ketone bodies in the blood

In some people with diabetes mellitus, the pancreas releases insufficient amounts of insulin or no insulin at all. Consequently, glucose goes largely undelivered.

In a desperate attempt to provide fuel, the body begins feeding on itself -- that is, it breaks down muscle and fat to burn as fuel. Ketone bodies are a byproduct of this process.
Ketone bodies consist chemically of three substances (beta-hydroxybutyric acid, acetoacetic acid, and acetone).
 
When ketone bodies are released, they enter the bloodstream, acidify the blood, and are eventually excreted mostly in urine. (One type of ketone body exits via the lungs.) Without treatment, glucose and ketone bodies may build to dangerous levels in the blood. Stress and illness can increase the risk of glucose and ketone buildup.

Symptoms:

• thirst, frequent urination

• dehydration

• nausea, vomiting

• heavy breathing

• dilation of the pupils and confusion resulting from the toxic effects of ketone bodies and acid accumulation on the brain

• a breath odor resembling the smell of fruit

Treatment: with insulin and intravenous fluids, can restore normal levels of blood sugar and end ketoacidosis and ketonuria

Steroids

In term of structure, steroids differ considerably from triglycerides or phospholipids, cholesterol is an important molecule in the body because it serves as the precursor for the steroid hormones produced by gonads and adrenal cortex.

Is from cholesterol.

Prostaglandins

Is any member of a group of lipid compounds that are derived enzymatically from fatty acids and have important functions in the animal body. Are found in virtually all tissues and organs.

Role:

• cause constriction or dilatation in vascular smooth muscle cells

• sensitize spinal neurons to pain

• constrict smooth muscle

• regulate inflammatory mediation

• regulate calcium movement

• regulate hormone regulation

• control cell growth