Compendium Review Cells and Genetics

Table of Contents
1.Cells are fundamentals of life
2.Characteristics and molecules of life
3.Cell structure and function
4.Cell organelles and metabolism
5.Tissue types








http://www.d.umn.edu/cla/faculty/troufs/anth1602/pcweek09.html


Cells are tiny structures that are a major part of every living thing. Cells consist of molecules which are non living particles that consist of smaller particles called atoms. All organisms consist of one or more cells and the cells is the basic structure of of all organisms. Also, all cells arise from exsisting cells.

There are several characteristics of life, including:

• All living organisms have cells. Cells are the fundamental building blocks of living things.


• Homeostasis is a stated of consistancy that every organism requires to live.


• All organisms need to take on molecules and energy from their surroundings to survive. Energy in adults is the key factor in transporting molecules, making protiens, and all basic body functions.


• All living things have a metabolism which is a chemaical reatction in the cells and tissues. There are two types of reactions, anabolic which transforms food substance into tisue and catabolic which breaks down food to create energy. Without millions of these reactions in a second, there would not be life.


• Living things must be able to adapt to their environments. The ability to respond to the stimuli of change is important to survival.


• All organisms are capable of reproduction and growth. These features are need to produce offspring and carry on life.


• Evolution is needed to make changes to species known as adaptations. These structural, functional, and behavioral changes are needed for survival and reproduction in all organisms.


• Every organism depends on earths ecosystem to survive. They need food, fiber, water, oxygen, and other natural ammenities. Earths ecosystem is the life support of the planet.
  

The Scientific Method is a technique use by scientists to test and prove an idea. We also use the scientific method in our day to day lives.There are four steps to the scientific method:


1.Hypothesis
2.Experiment/Observations
3.Conclusions
4.Theory

Critical thinking is also a beneficial process in analizing facts, issues and problems.

Atoms are made up of tiny particles called matter. The matter is made up of even smaller particles calles mass. The center of the atom is called the nucleus. The inside of the nucleus is made up of protons and neutrons. Protons are positively charged particles and neutrons are uncharged particles. As far as size goes, the neutrons has less mass than the protons. This would make the nucleus of the atom positively charged because the protons are positive and the neutrons are neutral.

Surrounding the nucleus is the electron cloud. The electron cloud is made up of electrons that are negatively charged. This electron cloud makes up most of the volume of the atom. Given the positively charged nucleus and the negatively charged electron cloud, the atom itself is electrically neutral.

Elements are pure substances that contain only one atom. The periodic table of elements is a table that shows the statistics of each element.

http://www.dayah.com/

The number above the element is the atomic number. The atomic number tells how many protons are in the nuclei. It is also the number of electrons. Carbon, oxygen, hydrogen, and nitrogen are four elements that make up 98% of all living things

Isotopes are another form of element that differs in the number of neutrons that it has. This does not affect the atom much other than it can change its weight. Isotopes release small burts of energy from their nuclei. These energetic emissions are called radiation. Radiation helps the atom by carrying away energy and mass therefore making the atom more stable. Although radiation has been proven to be beneficial for the body, it also comes with risks. It can cause mutation which can damage molecules in the body cells and can cause changes in genetic material.

Molecules are what you get when two atoms combine. A substance made up of two or more atoms is a compound. The smallest part of the compound that still holds the properties of the compound are molecules. Atoms in the molecules join together by bonds. This makes for a very stable configuration. There are ionic bonds and covelant bonds.

http://www.accessexcellence.org/RC/VL/GG/ecb/covalent_ionic_bonds.html



The picture on the right is an ionic bond. Ionic bonds are when an atom loses an electron and the other atom gains an electron. The atom that loses an electron becomes positively charged and the atom that gains an electron becomes negatively charged.


The picture on the left is of a covelant bond. A covelant bond is when two atoms share electrons. The electrons actually circle around both atoms holding them together. This bond is usually much stronger than an ionic bond.


There are a couple of other bonds including a polar covelant bond and hydrogen bonds. Polar covelant bonds are when two atoms are sharing an unequal number of electrons. A hydrogen bond is a bond on different molecules where the atoms are slightly charged.





A very important molecule is water. Water has a single atom of oxygen and it is bonded by two atoms of hydrogen.







http://en.wikipedia.org/wiki/Image:Water_molecule.svg

Water is the key factor in all living organisms.Water makes up approxamately 60-70% of the body therefore it is very critical in our body functions including keeping our joints lubed and transporting food from the mouth to the stomach. It also helps our body to maintain homeostasis.

The human body must maintain an average ph level to keep normal body functions. Your ph level measures acid. You have acids and you have bases. Acids have H+ and too much can be harmful so there is bases that remove H+. The body naturally has ph buffers that prevent changes in your ph. PH buffers are a combination of chemicals that work towards keeping your ph normal.

There are four other groups of molecules including carbohydrates, lipids, protien, and nucleic acids. There are subunits in each of these molecules that are called marcomolecules.
Carbohydrates are organic molecules that range in size from simple sugars to starch. They are for supplying energy to the cells.
Lipids are a very diverse group that includes fats and steroids. These are a source of energy and structure.
Protiens are are long molecules made up of smaller molecules called amino acids.This speeds up chemical reactions in the body.
Nucleic acids is the complex group that includes DNA.

Microscopes are one of the only way to see cell becuse they are so small that in most cases you cannot see them with the naked eye. There are two kinds of microscopes the light microscope and the electron microscope. The electron microscope is better because it magnifies things much more than the light microscope.






usamicroscopy.info




The cell consists of two main compartments the nuclear and the cytoplasmic. The nuclear or nucleus contains the genetic material and controls the function and structure of the cell. Cytoplasm forms a nutrient rich pool that the cell needs to draw from to make metabolism possible. This pool contains molecules like water, protien, ions, nutrients, vitamins, dissolved gasses and waste products.

Cells contain many organelles. Each organelle carries out a specific function. Made up of protien tubules and filiments in the cytoplasm lies in the cytoskeleton. This supports and organizes the cells activity and in turn helps efficiency.

The plasma membrane controls what goes in and out of the cell. It is the outermost layer of the cell and it determins what is in the cell. The plama membrane consists of lipids, protiens, and carbhydrates which are described above. The plasma membrane provides energy, insulates, stores energy, and is a vital part for homeostasis and survival. This membrane also plays a key role in communication with other cells. In adition to that it has its own individual identification.

Inside the protien molecules are smaller molecules know as amino acids. Amino acids contain a central carbon atom.

There are five basic means of transporting molecules in and out of the cell. The first is diffusion. This is simple in that it transferes molecules from areas of higher concertration to areas of lower concertration. The next way is carrier protiens. These protiens transfer molecules and ions acroos the membrane and how it does this is not known. Another mechanism for transportation is active transport. Active transport helps the carrier protiens move molecules across membranes. Endocytosis is the act of moving molecules into the cell using phagocytosis and pinocytosis. The opposite of endocytosis is exocytosis. This is the release of molecules out of the cell.

Osmosis is another word for diffusion. It is the movement of water acros a cell from an area of high concertration to an area of low concentration.

Organelles- carry out key functions

Nucleus is an organelle that contains chromatin which is threadlike fibers of DNA. A chromasome is a chomatin that has a strand of protien. Has nucleoli and they appear to be small clear and oval structures under the microscope. This organelle has a semifluid material called nucleoplasm that contains protien, water, and other small molecules.

Mitochondria releases stored energy that is usually sugars and fats. It has an outer and inner membrane that varies from cell to cell

Protien production is made up of three organelles.

• Endoplasmic reticulum- membranous channel that has an intracellular network. Some are covered in ribosomes and they are known as rough endoplasmic reticulum (RER). These protect protien and transfer it to the next organelle which is the Golgi Complex


• Golgi complex-Membranous sacs that sort molecules and seperates enzymes to make sure that they get to where they belong. It also modifies protiens by adding carbohydrates or other molecules.


• Ribosomes-has messeger RNA and synthesises protien
  

Secretory vesicles are tempature storage sites for hormones and digestive enzymes.

Lysosomes are membrane bound and they contain digestive enzymes. They break down material phagocytized by cells and they attach to food vacuoles and release enzymes into them for digestion. They rid the body of bad or old cells and they are very important to embryonic developement.

Flagella permits movement of the cell. Sperm cells have flagellum and each flagellum has a basal body. It is that body that provides structure and anchors it

Cilia allows movement across the cells and is vital for protecting major organs. Its structure is very simular to the flagella.

Pseudopodia are cytoplasmic projections that are sent out during amoeboid motion.

Energy and Metabolism of Cells

Cells get their energy from breaking down glucose and tryglycerides.The complete breakdown of glucose is called cellular resiration. This feature requires oxygen to break down and once broken down it is in 6 molecules. These release a lot of energy.

Cellular Respiration takes place in 4 steps

• Glycolysis-breaks down into two seperate pyruvate molecules



• Transition Reaction-one carbon is knocked off the pyruvate molecule



• Cytric Acid Cycle-completes the breakdown of glucose



• Electron Transport System-transfers protiens to carrier molecules

Enzymes are essential to the chemical reations that happen in the cell. They are a large globular protien that is the active site where the chemical reaction occurs

Fermentation occurs when oxygen gets low. It can cause muscle fatigue by making the cell anerobic with the depleting oxygen. It is also the cheif source of energy for bacteria.

Types of Tissues

There are four primary types of tissues. Tissues are formed by cells.

• Epithelial tissue



• Connective tissue



• Muscle tissue



• Nervous tissue

Epithelial tissue forms glands and forms linings for covering organs. There are two types of epitelial tissue and they are glandular and membranous. Glandular are clumps of cells and the exocrine gland remains attached to the epithelium. Membranous are the lining of vital organs.

Cells, tissue, and organs can be corralated between structure and function.

Epidermis is the outer layer of skin that consists of many cell layers stratified squamous epithelium.

Connective tissue binds the cells and the organs of the body together and it has two basic components and they are cells andextracellular material. There are two types of connective tissues and they are connective tissue proper which is an important structural component and the other one is specialized connective tissues which are bone, cartilage, and blood. There is also dense and loose connective tissue. Dense is tightly packed and loose is made up of protien and loosly packed. It can be found around blood vessels and skeletal muscles. Fibroblasts is also connective tissue that repairs damaged or torn body tissue. Macrophage is a protective cell that contains many lysosomes and prevents bacteria from spreading.Fat cells are most distinctive because they are very large and they are mostly fat globules. Adipose tissue is what you call a large amount of fat cells in one area.

missinglink.ucsf.edu/lm/IDS_101_histo_resourc...

Specialized connective tissue performs many functions to help with homeostasis. There are three types of specialized connective tissue

• Cartilage is cells that imbed in an impenatratable extracellular material and connective tissue packs around it. It is nourished by diffusion form blood vessels. There are three types of cartilage.
  

1. hyaline- has numerous of collagen fibers that appear white

2. elastic-has wavy fibers and gives flexability

3. fibrocartlige-in areas that experience tension and pressure and form outerlying tissue known as intervertebal tissue.

• Bone provides structure and supports. It protects the vital organ and maintains blood calcium levels. It is a homeostatic organ that has salt crystals including calcium phosphate and hydroxide ionds that makes the bones hard. There is two types of bone tissue and they are compact which is dense and hard and there is spongy which is calcified collegen plates. On the surface of these plates are osteoblasts which are a type of bone that produces collagen.
  

Blood is refered to as a vascular tissue made of extracellular materail. It contains red and white blood cells. The red are responsible for 45% of blood volume and plasma which is extracellular material makes up the remaining 55%. Red cells transport oxygen while white cells rid the body of foreign organisms.

Muscule tissue contracts when it is stimulated. It is an excitable tissue that moves body parts and the heart muscle which pumps blood. There are three types of muscle tissue.

• Skeletal which is attached to the skeleton and causes body parts to move. They are in long cylinders and they cannot divide



• Cardiac muscle is an involuntary muscle that branchs andinterconnects freely. It provides a pathway for electrical impulses between cells.



• Smooth muscle occurs singlely or in small groups. There are small rings of cells that surround blood vessels. They are sheets in the walls of organs
  
  

www.corel.com

Nervous tissue is specialized cells that conduct impulses. There are two cells and they are conducting cells and neuroglia which forms the brain, spinal cord and nerves.

www.washington.uwc.edu