what is a protoplasm?
a thick viscousm, suspension substance that constitutes the physical basis of all living activities
what are the properties of a cell?
simple life forms consist of how many type of cells?
more complex life forms are made up of how many types of cells?
many types of cells
what is a tissue?
- groups of cells that perform the same activity
- epithelial, connective, muscular and nervous
what is an organ?
- groups of tissues that perform a specialized function
- stomach- composed primarily of epithelial and muscle tissue
what does a group of organs form?
- a system
- GI or respiratory system
what is the highest level of organization?
a person or bird
what are organic compounds?
what are inorganic compounds?
which one, organic or inorganic compound, is suspended or dissolved in water?
a cell is made up of how much water?
what are the roles of water in a cell?
- helps hold and transport substances in the cell
- chemical activities take place in the cell
- helps maintain constant temperature
- w/o water, cells would be vulnerable to extreme changes in temperature
how does a cell move water in and out?
- by osmosis
- amount determined by osmotic pressure
- osmotic pressure determined by the concentration of mineral salts inside or outside of cell
what happens when there's too much or too little water in the cell?
- too much- cell ruptures
- too little- cell collapes
what happens when there's too little sodium inside the cell or too little potassium outside the cell?
will cause water to be pulled outside the cell causing collapse
what is hypertonic?
a solution that causes a cell to shirnk
what is hypotonic?
a solution that causes a cell to swell
what is isotonic?
having an osmotic pressure equal to that of circulating blood
what are the benefits of mineral compounds and salts?
- minerals prevent cramping
- salts aide in the production of energy and the conduction of nerve impulses
what are the major classes of organic compounds?
- nucleic acids
what are proteins?
- large molecules formed by joining together simple units known as monomers into a long chain
- building block of a cell
protein makes up how much in a cell?
a protein is important to which types of tissues?
- structure of skin
what are the functions of proteins?
- building new tissue
- repair injured or broken down tissue
- intercellular messengers
- composition of enzymes
what are enzymes?
large protein molecules that control the speed of most chemical reactions inside the cell
what are amino acids?
- basic composition of proteins
- about 80 are found, 20 are essential to humans
the more specialized the cell is it is more resistant or nonresistant to radiation?
what is hemolysis?
too much water can rupture cell
what are lipids?
- make up about 2% of a cell
- excess energy is stored for later use
how do lipids form?
sugar molecules, from which cells usually get their energy, are converted into lipids for storage if not needed for current use
are lipids water soluble?
- but are in alcohol, ether, oil and chloroform
what are the classifications or types of lipids?
- those stored in the inside the cell for energy
- those used to form the cell membranes as a thermal cushion
- also for production of steriods, cholesterol, testosterone, and estrogen
- long chain lipids important for pigmentation such as eye color
- involved with muscle contraction, blood vessel constriction, cell reproduction, and inflammatory response
what are the functions of lipids?
- storage of energy
- important component of cell membrane
- protection against cold and heat
- assistance in digestive process
- components of substances such as hormones
what are carbohydrates?
- make up about 1% of the cell
- provide most of the cell's' energy
- sugars and starches are typical carbohydrates
- stored primarily in the liver and muscles
- they release large amounts of energy when the bonds are broken through metabolism
what are the classifications of carbohydrates?
what are monosaccharides?
- glucose or fructose
- primary source of cell energy
what are disaccharides?
- sucrose, lactose, and maltose
- not easily metabolized
- storage form of energy that can be converted to glucose and used for energy requirements
what are polysaccharides?
- starch, dextrin, cellulose and glycogen
- used as an energy source
- cellulose is used for structural purposes
what are nucleic acids?
- blueprint for reproduction
- a template for protein synthesis
- transport mechanism to join materials necessary to build proteins
- control mechanism to regulate the cell's metabolism and reproduction
what are the two types of nucleic acids?
what are the two major sections of the cell?
are both cytoplasm and the nucleus covered with protoplasm?
- nucleoplasm- protoplasm inside the nucleus
- cytoplasm- protoplasm outside the nucleus
what are the structures within the protoplasm called?
- each organelle has a function necessary for cell health and survival
what does the nucleus contain?
- the genetic and metabolic information of the cell
- similar to the brain of the organism
- this controls how that organism functions in its environment
what are the components of the nucleus?
- nuclear envelope
- nuclear sap- the liquid portion of a cell nucleus
what is the nuclear envelope?
- membrane that separates the nucleus from the cytoplasm
- double-walled structure with a space within the walls
which structures are the only ones that can pass through the nuclear envelope?
- some proteins that are incorporated into the nuclear structure
what are chromosomes?
linear threads in the nucleus
what are chromosomes composed of?
- proteins and DNA
- DNA encodes the information that controls that cell's metablosim and reproduction
- DNA is considered the genetic material and serves as a template to produce an exact copy of itself used in cell division
how many chromosomes do humans contain?
46 (23 pairs)
A DNA structure contains what?
- deoxyribose- sugar in the backbone
- phosphoric acid- a phosphate in the backbone
- Four introgenous bases- the actual genetic code
what are the four nitrogenous bases within a DNA?
what does a DNA look like?
- a twisted ladder
- the bases are the rungs
- the backbones are the sides
what are the backbones of a DNA made of?
- phosphoric acid
what are genes?
- the basic unit of heredity
- made up of long squences of DNA on a chromosome
- genes are found in pairs
what do genes accomplish?
- some govern the number of organs and limbs
- others determine heigh, skin and eye color and gender
what is a nucleolus?
a single spherical structure usually found in the nucleus
what is the nucleolus composed of and what does it do?
- composed of RNA(ribonucleic acid)
- controls protein synthesis
what are the similarities and differences of a nucleolus and a DNA?
- similar structure to DNA
- nucleolus' sugar is ribose as opposed to deoxyribose
- the base uracil replaces thymine
- it is a single helix
what are the forms of RNA?
- messenger RNA
- transfer RNA
- ribosomal RNA
what does a messenger RNA do?
carries the code for specific amino acid sequences from DNA to cytoplasm for protein synthesis
what does a transfer RNA do?
transfer amino acid groups to ribosome for protein synthesis
what does a ribosomal RNA do and where does it live?
- exists in the ribosomes
- thought to assist in protein synthesis
where do metabolic functions such as anabolism and catabolism occur?
- these functions are used in energy conversion and serves to store or release energy
what is anabolism?
the duplication of DNA, production of hormones, and converting of sugars to starches
what is catabolism?
the breaking of the carbon-hydrogen bond to release the energy of glucose
what does the cell membrane consist of and what does it do?
- composed of lipids and membranes
- transport proteins assist in the passage of substances through the membrane and throughout the cell
what are ribosomes and what are they made of?
- function to synthesize proteins
- made of ribosomal RNA
what is the endoplasmic reticulum and what does it do?
- a connecting netweork between the nucleus and cytoplasm
- used to build carbohydrates and lipids and detoxification
what is the mitochondria and what does it do?
the source of energy in the cell
does a mitochondria contain their own dna?
which muscle cells have the greatest number of mitochondria because of their great need for energy?
cardiac muscle cells
what is the golgi apparatus and what does it do?
- located near the nucleus
- collect molecules produced in one part of the cell, modify, or syntesisze new molecules, package and distribute them to other parts of the cells
- analogous to the digestive system
what are lysosomes?
- part of the intracellular digestive system
- break down proteins, carbohydrates, lipids, and nucleic acids and recycle them
- analogous to the stomach
what is mitosis?
- cell division of smatic cells
- each daughter cell contains the same number of chromosomes as the parent cell
- a cycle that has 5 phases, 4 are cell-reproduction phases
what are the 5 phases of mitosis?
what happens during interphase?
- the period between cell division
- has 3 subphases
what are the 3 subphases of interphase?
what is the G1 subphase?
the first subphase where the cell spends most of its life and where it grows
what is the S phase?
the DNA is replicated but stays attached to the centromere, a region in the middle of each chromosome
what is the G2 phase?
- the final subphase in which the organelles are reproduced
- spiral filaments called chromatids reproduce
what happens during prophase?
- the chromatin granules of the nucleus become organized into chromosomes
- each consist of two chromatids
- chromosomes become shorter and more compact
- the nuclear membrane and nucleoli disappear, the centriole divides, and two daughter cells move to opposite poles of the cell
what happens during metaphase?
- the paired chromatids arrange themselves in an equatorial plane midway between the two centrioles forming the plane
- cell division can be stopped and radiation damage can be examined under a microscope
what happens during telophase?
- each daughter cell now contains the same genetic material as the parent cells
- two complete cells results from the cytoplasm's becoming separated into two parts
what is meiosis?
cell division that produces germ cells or reproductive cells
how many successive divisions of the mother cell occur in meiosis and how many daughter cells are produced?
- 2 divisions
- 4 daughter cells
how many chromosomes are passed down in meiosis?
only half the number compared in somatic cells
compare malignant cells to normal cells
- bigger nucleus
- small cytoplasm
- increase mitotic activity (division)
- in normal tissue, cells usually stick together
- some types of cancers metastasize by allowing cells to break free of the tumor site