Radiation Biology: Ch. 6 pg. 88-98

what is biology

a science that explores living things and life process

the basic units of all living mater that are essential for life, each one has a predetermined task to perform in support of the body

cells

what does normal cell function enable the body to do

maintain homeostasis or equilibrium without difficulty

what is the ongoing process for a cell

obtaining energy and converting it to support their vital functions

what will happen to a cell if radiation damages the components involved in molecular synthesis beyond repair

the cells will either die or behave abnormally

protoplasm:

the chemical building material for all living things, involved in many processes

what is protoplasm consisted of

organic and non organic materials-macromolecules

what are the primary biomolecules that make up protoplasm

carbon, hydrogen, oxygen, and nitrogen

what are the most important inorganic substances

water and mineral salts

organic materials must contain _____

carbon

inorganic materials have _____

no carbon

3 categories of inorganic compounds

acids, bases, and salts

salts are commonly referred to as _____

electrolytes

primary inorganic substance in the body

water (80-85%)

water: (5 things)

• solvent

• transport vehicle for materials

• maintains body temp

• lubricates joints and GI tract

• cushion for brain and lungs

salt: (7 things)

• correct proportion of water in cell (osmosis)

• proper cell performance

• creation of energy

• conduction of impulses along nerves

• can be broken down into ions in the cell

• potassium contributes to most of the positive ions and phosphorous make up the negative ions

• potassium helps maintain adequate intracellular fluid

what are the 4 major classes of organic compounds

proteins, carbohydrates, lipids, nucleic acids

proteins make up __% of cell content and contains the most ____ per molecule

15%, carbon

what are proteins essential for

growth, construction of new tissue, and repair of injured or debilitated tissue

how are proteins formed

by combining amino acids into long chain like macromolecules-up to thousands of atoms connected by peptide bonds

involves 22 different amino acids, their order determines the precise function of protein molecule

protein synthesis

what organizes amino acids into certain sequences to form specific different types of proteins

chromosomes and genes

where are structural proteins found and what is their function

found in muscle, provide the body with its shape, form, heat, and energy

enzymatic proteins function

• moderate the cells various physiologic activities

• proper functioning of the cell depends upon the enzymes

mend damages molecules and are therefore capable of helping the cell recover from small amounts of radiation induced damage

repair enzymes

when do repair enzymes work most efficiently

in the diagnostic energy range

chemical secretions produced by the endocrine glands and carried by the blood system to influence activities of other parts of the body

hormones

regulate functions such as growth and development

hormones

protein molecules produced in bone marrow

antibodies

what are antibodies

primary defense mechanism of the body against infection and disease

attack foreign objects such as bacteria or virus-antigens

carbohydrates make up __% of cell composition, and are also referred to as _______

1%, saccharides

what do carbohydrates include

starches and sugars

primary purpose of carbohydrates

to provide fuel for cell metabolism

three types of carbohydrates:

simple sugars, disaccharides, polysaccharides

simple sugars:

monosaccharides, such as glucose

disaccharides:

are more complex, 2 units of simple sugars linked together such as sucrose or lactose

polysaccharides:

several or many molecules of sugar, plant starches, and animal glycogen are the two most important ones

referred to as fats or fat-like substances

lipids

lipids make up __% of cells composition

2%

water-insoluble macromolecules

lipids

what are lipids made up of

1 molecule of glycerin, 3 molecules of fatty acid

_____ are structural components of cell membranes, present in all tissues of the body

lipids

6 functions of lipids:

1. act as reservoirs for long-term storage of energy

2. insulate and guard the body against the environment

3. support and protect organs such as kidneys and eyes

4. provide essential substances for growth and development

5. lubricate joints

6. assist in the digestive process

nucleic acids make up __% of cell composition, and make up smaller structures called _______

1%, nucleotides

two major types of nucleic acids:

1. DNA

2. RNA

2 long sugar phosphate chains that twist around each other in double helix

DNA

how is DNA linked

pairs of nitrogenous bases

where is DNA located

in the nucleus of the cell

4 nitrogenous bases in DNA

Adenine

Cytosine

Guanine

Thymine

adenine and guanine are ______

purines

cytosine and thymine are _______

pyrimidines

base bonding is limited to ___&___ , ___&___

adenine & thymine , cytosine & guanine

functions of DNA:

1. contains all information cell needs to function

2. carries all information needed for cell replication and regulating cellular activity

3. determines characteristics of a person, by regulating sequence of amino acids in persons proteins during synthesis

different sequence of amino acids produce different proteins

genetic code

protein characteristics determine ________, and that determines ____________

cell characteristics, characteristics of the individual

what can DNA not directly influence because it is found in nucleus of a cell

cannot directly influence cellular activity such as growth and differentiation, which occurs in cytoplasm

DNA regulates cell activity directly or indirectly?

indirectly

how does DNA regulate cell activity indirectly

by transmitting its genetic information outside the nucleus by reproducing itself in form of messenger RNA

resembles half of DNA molecule

RNA

which pyrimidine is replaced by uracil

thymine

where is RNA located

in the nucleolus of the nucleus

what is RNA responsible for

making proteins out of amino acids

carries genetic code from the nucleus to the ribosomes where proteins are produced

mRNA

mRNA delivers its genetic code to _____

tRNA

transports amino acids from their areas in the cell to the ribosomes where they are arranged and attached in specific order to form the correct protein

tRNA

most radiosensitive macromolecule

DNA

in terms of sensitivity to radiation are proteins more or less sensitive than nucleic acids

less

in terms of radiation sensitivity _____ lies between DNA and proteins

RNA

tiny rod shaped bodies composed of DNA

chromosomes

normally there are ____ chromosomes, ____ pairs in somatic cell

46, 23

DNA that makes each chromosome is divided into hundreds of segments called ____

genes

there are approximately how many genes/cell

75,000

basic unit of heredity

genes

what is the human genome

the total amount of genetic material (DNA) contained within the chromosomes of a human being

mapping:

process of locating and identifying the genes

what is the human genome project

• provides genetic testing to evaluate for conditions

• many ethical, legal, and social issues raised by this research-like manipulating human genes