Chapter 6 Flashcards
Overview of Cell Biology
What is biology?
a science that explores living things and life processes
What are cells?
-Basic unit of all living matter
-Essential for life
-Fundamental components of structure, development, growth, and life processes in the human body
-Exist in a multitude of different forms
What are some functions of the cell?
-Conduction of nerve impulses
-Contraction of muscles
-Support various organs
-Transport body fluids such as in blood
What happens if a cell is mature?
it is highly specialized and has predetermined tasks to perform in support of the body
What can the cell do?
-Move
-Grow
-React
-Protect themselves and repair damage
-Regulate life processes
-Reproduce
What are requirements for the body?
-Provide food as a source of raw material for the release of energy
-Supply oxygen to help break down the food
-Have enough water to transport inorganic substances (calcium and sodium) into and out of the cell
What is the benefit of proper cell function?
Enables the body to maintain homeostasis or equilibrium despite any changes the body may undergo such as stress, exercise, injury, or disease
What are the effects of ionizing radiation on the cell?
Damaging the components of the cell involved in molecular synthesis beyond repair
-Cell behave abnormally
-Cells die
What is protoplasm?
a chemical building material for all living things
What does the protoplasm carry?
-Complex process of metabolism
-The reception and processing of food and oxygen
-The elimination of waste products
What does the protoplasm consist of ?
large and small molecules called macromolecules, which consist of organic compounds and inorganic materials
What are organic compunds?
contains carbon, hydrogen, and oxygen
What are inorganic materials?
do not contain carbon (water & mineral salt)
What are the four major classes of organic compounds that compose the cell?
-Proteins
-Carbohydrates
-Lipids (fat)
-Nucleic Acid
What is the basic constituent of all organic matter?
carbon
What makes life possible?
by combining hydrogen, nitrogen, and oxygen
What organic compound contains the most carbon?
proteins
How much of the cell is protein?
15%
What is protein essential for?
-Growth
-The construction of new body tissue
-The repair of injured or debilitated tissue
How is protein formed?
when amino acids combine into long, chainlike molecular complexes
How much of the cell is water?
80-85%
How much of the cell is carbohydrates?
1%
How much of the cell is nucleic acids?
1%
How much of the cell is lipids?
2%
How many different amino acids are involved in protein production(protein synthesis)?
22
What determines the precise function of each protein molecule?
The order of arrangement of the different amino acids
What are enzymatic proteins(enzymes)?
-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
What are structural proteins?
-Provide the body with its shape and form
-Provide a source of heat and energy for the body
-Example: found in muscle
What do repair enzymes do?
can mend damaged molecules and are therefore capable of helping the cell recover from a small amount of radiation-induced damage
-They are vital for the survival of the cell
-Works effectively in both the diagnostic and therapeutic energy ranges
What are antibodies?
Protein molecules produced by specialized cells in the bone marrow called B lymphocytes
When are antibodies produced?
When other lymphocytes in the body (T lymphocytes) detect the presence of molecules that do not belong to the body
What do antibodies do?
Chemically attack any foreign invaders or antigens
What is a lymphocyte?
a white blood cell
What are hormones?
Chemical secretions manufactured by various endocrine glands and carried by the bloodstream to influence the activities of other parts of the body
What do hormones do?
Regulate body functions such as growth and development
What is an example of hormones?
Hormones produced in the thyroid gland control the metabolism throughout the body
What do carbohydrates include?
starches and various sugars
What is the function of carbohydrates?
as short-term energy warehouses for the body
What is the primary function of carbohydrates?
To provide fuel for cell metabolism
Where are carbs most abundant?
In the liver and in muscle tissue
What are lipids (fats)?
-Organic molecules
-The structural parts of the cell membranes
-Perform various functions in the body
What are nucleic acids?
-Very large, complex macromolecules
What are nucleic acids made of?
Nucleotides
What are two types of nucleic acid cells?
DNA & RNA
What is DNA?
Double stranded macromolecule contained in the nucleus
What does DNA contain?
all genetic information of the cell
What are the two functions of DNA?
-Replication
-Control cellular activity
How is DNA arranged?
Into long thread-like structures called chromosomes
How many chromosomes do normal humans have?
46 each (23 pairs)
What is RNA?
Single stranded and function as the messenger system for DNA between DNA and the ribosomes where synthesis occurs
-receives a set of chemical instructions from DNA
What are chromosomes?
tiny-rod shaped bodies that under a microscope appear to be long thread-like structures that become visible only in dividing cells
What are chromosomes composed of?
Protein and DNA
How many chromosomes does a normal human have in each somatic (nonreproductive) cell have?
46 different chromosomes (23 pairs)
How may chromosomes does each reproductive (germ cell) have?
23 each
What are genes?
Segments of DNA that serve as the basic units of heredity; Each one contains information responsible for directing cytoplasmic activity, controlling growth and development of the cell, and transmitting hereditary information
-Basic units of heredity-
What do genes control?
The formation of proteins in every ell through the intricate process of genetic coding
Where do inorganic compounds occur?
In nature independent of living things; they are acids, bases, and salts (electrolytes)
What are the most important inorganic substances?
Water & Mineral Salts
Water comprises how much of the body’s weight?
80-85%
It is imperative for the correct amount of what in a cell to be maintained?
Water
What is the function of water within the cell?
-Is the medium in which the chemical reactions that are the basis of metabolic activities occur
-Acts as a solvent, keeping compounds dissolved so that they can more easily interact, and their concentration may be regulated
What is the function of water outside the cell?
-Functions as a transport vehicle for materials the cell uses or eliminates
-Is responsible for maintaining a constant body core temperature of 98.6F
-Lubricates both the digestive system and skeletal articulations
-Protects organs such as the brain and lungs
What is the function of mineral salts within the cell?
-Keep the correct proportion of water in the cell to maintain osmotic pressure
-Necessary for:
-Proper cell performance
- Creation of energy
- Conduction of impulses along nerves
What are the components of the normal human cell?
-Cell Membrane
-Cytoplasm
-Nucleus
What is the difference between cytoplasm and protoplasm?
Protoplasm includes the nucleus
What are the two cell classifications?
Somatic cells & Gonadal cells
What are somatic cells?
comprise all types of tissues in the body(skin, muscle, nerves)
What do somatic cells do?
-Carry out life function of the individual
-Pass on identical genetic information to daughter somatic cells
What are gonadal cells?
Responsible for continuance of species
What do gonadal cells do?
-Contain ONLY 23 chromosomes
-Spermatogonium (sperm) : male gonadal cell
-Oogonium (egg) : female gonadal cell
What are the two types of cell division?
Mitosis & Meiosis
What is mitosis?
A process in which the nucleus first divides, followed by the division of the cytoplasm. A parent cell divides to form two daughter cells identical to it.
-Process occurs when all somatic cells divide
What is meiosis?
A process of reduction cell division
-Process that occurs when gonadal cells divide
-Process needed to create new/more sperm and egg cells
What is another name for cell division?
Cell proliferation
What is cell division?
The act of a single cell or group of cells reproducing or multiplying in number
What are the four phases of cell division?
1-Prophase
2-Metaphase
3-Anaphase
4-Telaphase
During which phase of cell division can radiation induce chromosome damage?
Metaphase
What is interphase?
phase before mitotic events
Mitosis makes _______ cells?
identical
What is uncontrolled cell growth?
Cancer
Are body cells dividing all the time?
No
What is prophase?
The beginning
What is metaphase?
Chromosomes line up in the middle, nuclei starts to disappear
What is anaphase?
Chromosomes start to pull to the sides of the cell
What is telaphase?
Chromosomes are pulled all the way to the sides of the cell, new nuclei are forming
What does mitosis create?
Forms 2 new cells, each with 46 identical chromosomes
What type of cells is most sensitive to radiation during mitosis?
Somatic Cells
What are the most sensitive types of somatic cells?
Blood (RBC) & Marrow
How many cell divisions occur in meiosis?
2
What process divides gonadal cells?
meiosis
What does radiation damage to DNA in meiosis result in?
The transmission of incorrect genetic information to future generations
What are the phases in meiosis?
-Prophase
-Metaphase
-Anaphase
-Telophase
-Production of 2 daughter cells, each with 23 chromosomes
-P2
-M2
-A2
-T2
-New set of daughter cells, each with 23 chromosomes (4 all together)
After meiosis is complete the 4 sperm or egg cells will all be __________.
different
Will the cells produced after meiosis be identical to the original cell?
No
What are monozygotic twins(identical twins)?
One egg splits into two after fertilization
What are dizygotic twins(fraternal twins)?
Two eggs are fertilized
