Chapter 6: Overview of cell Biology

Biology

a science that explores living things and life processes

cells

basic units of living matter

essential for life

fundamental components of structure, development, growth, and life processes in human body

protoplasm

chemical building material for all living things

carrier on the complex process of metabolism, the reception and processing of food and oxygen, and the elimination of waste products

organic compounds

proteins

carbohydrates

Lipids (fats)

Nucleic acid

carbon

the basic constituent of all organic matter

by combining with hydrogen, nitrogen, and oxygen , and it makes life possible

proteins

essential for growth, the construction of new body tissue, and the repair of injured or debilitated tissue

contains the most carbon of all the organic compounds

constitutes approximately 15% of cell content

enzymatic proteins

function as organic catalysts

control the cell’s various physiologic activities

cause an increase in cellular activity that in turn causes biochemical reactions to occur more rapidly to meet the needs of the cell

structural proteins

provide the body with its shape and form

provide a source of heat and energy for the body

repair enzymes

can mend damaged molecules and are therefore capable of helping the cell to recover from a small amount of radiation- induced damage

work effectively in both the diagnostic and therapeutic energy ranges

antibodies

chemically attack any foreign invaders or antigens (B and T lymphocytes)

B lymphocytes

protein molecules produced by specialized cells in the bone marrow

most radiosensitive

T lymphocytes

produced when other lymphocytes in the body detect the presence of molecules that do not belong to the body

hormones

regulate body functions such as growth and development

carbohydrates

include starches and various sugars

function as short-term energy warehouse for the body

provide fuel for cell metabolism

most abundant in the liver and in muscle tissue

lipids

are organic macromolecules

are structural parts of cell membranes

present in all body tissuen

nucleic acids

are very large, complex macromolecules

are made up of nucleotides

DNA and RNA are two types

DNA

contains all the information the cell needs to function

carries the genetic information necessary for cell replication

determines a person’s characteristics by regulating the sequence of amino acids in the person’s constituent proteins during synthesis of these proteins

RNA

DNA regulates cellular activity indirectly, transmitting its genetic information outside the cell nucleus by reproducing itself in the form of mRNA

Uracil replaces thymine

Transfer RNA

receives genetic code from mRNA

at least 22 exist

combines with individual amino acids from different areas of the cell and attaches them to the ribosomes, where amino acids are arranged in specific orders to form chainlike protein molecules

ribosomal RNA (rRNA)

its function is to assist in the linking of mRNA to the ribosome to facilitate protein synthesis

46

normal human have __ different chromosomes

23

normal human chromosomes have __ pairs

Genes

segments of DNA that serve as the basic units of heredity

control the formation of proteins in every cell through the intricate process of genetic coding

inorganic compounds

compounds that do not contain carbon

occur in nature independent of living things; they are acids, bases, and salts

water and mineral salts are the most important inorganic substances

water comprises

approximately 80% to 85% of the body’s weight

within the cell

the medium in which the chemical reactions that are the basis of metabolic activities occur

outside the cell

functions as a transport vehicle for materials the cell uses or eliminates

is responsible for maintaining a constant body core temperature

lubricates both the digestive system and skeletal articulations

protects organs such as the brain and lungs

98.6

constant body core temperature

function of mineral salts within the cell

keep correct proportion of water in the cell to maintain osmotic pressure

necessary for proper cell performance, creation of energy, conduction of impulses along nerves

Ions

constituents of salt, via chemical reaction cause materials to be altered, broken down, and recombined to form new substances

cell membrane

functions as a barricade to protect cellular contents from their environment and controls the passage of water and other materials into and out of the cell

performs elimination of wastes and refining of material for energy through breakdown of the materials

endoplasmic reticulum

enables the cell to communicate with the extracellular environment and transfers food from one part of the cell to another

synthesize products for cell use

golgi apparatus

unites large carbohydrates molecular and combines them with proteins to form glycoproteins; transports enzymes and hormones through the cell membrane so that they can exit the cell, enter the blood stream, and be carried to areas of the body in which they are required

mitochondria

produce energy for cellular activity by breaking down nutrients through process of oxidation

lysosomes

dispose of large particles such as bacteria and food, as well as smaller particles; also contain hydrolytic enzymes that can break down and digest proteins, certain carbohydrates and the cell itself if the lysosome’s surrounding membrane breaks

ribosomes

manufacture the various proteins that cells require

composition of protein and RNA

centrosomes

plays an important role in organizing the formation of the mitotic spindle during cell division

nucleus

contains the genetic or hereditary material, DNA, and proteins. Also contains the nucleolus

controls cell division and multiplication and the biochemical reactions that occur withing the cell

also directs protein synthesis

DNA

contains the genetic material; controls cell division and multiplication and biochemical reactions that occur within the living cell

nucleolus

holds a large amount of RNA and synthesizes ribosomes

cytoplasm

location of metabolic activities

enclosed by a cell membrane

golgi complex

package for export, synthesize carbs, bind organic compounds

cell division

the multiplication process whereby one cell divides to form two or more cells

mitosis

a process in which the nucleus first divides, followed by the division of the cytoplasm

occurs when all somatic cells divide

results in an approximately equal distribution of all cellular material between the two daughter cells

meiosis

a process of reduction cell division

occurs when genetic cells divide

makes germ cells

prophase

chromosomes move toward center of cell

spindles form within the cell, extending from one end to the other

metaphase

chromosomes align at the center of the cell

each chromosome attaches to a spindle as its centromere

Anaphase

the chromatids migrate along the spindle to the opposite poles of the cell

telophase

nuclear membrane forms around genetic material at poles

division of cytoplasm and indentation of cell membrane until two distinct cells are formed

process of meiosis

special type of cell division that reduces the number of chromosomes in each daughter cell to half of the number of chromosomes in the parent cell

monozygotic twins

identical twins

dizygotic twins

fraternal twins

polyzygotic siblings

more than two