Compendium Review Topic One- Cells

Table of Contents

Exploring Life and Science

• The Characteristics of Life


• Humans Are Related to Other Animals


• Science as a Process


• Making Sense of a Scientific Study


• Science and Social Responsibility

Chemistry of Life

• From Atoms to Molecules


• Water and Living Things


• Molecules of Life


• Carbohydrates


• Lipids


• Proteins


• Nucleic Acids

Cell Structure and Function

• What is a Cell


• How Cells are Organized


• The Plasma Membrane and How Substances Cross It


• The Nucleus and the Production of Proteins


• The Cytoskelaton and Cell Movement


• Mitochondria and Cellular Metabolism

Organization and Regulation of Body Systems

• Types of Tissues


• Connective Tissue Connects and Supports


• Muscular Tissue Moves the Body


• Nervous Tissue Communicates


• Epitheal Tissue Protects


• Cell Junctions


• Integumentary System


• Organ Systems


• Homeostasis

Chapter One Exploring Life and Science

The Characteristics of Life
1. Organization- atoms combine to make molecules that then make up a cell. Groups of cells form tissues. Several types of tissues form an organ. Each organ belongs to an organ system. Organ systems work together to reach a common goal. A collection of organ systems make up an organism. Members of one species in a particular area are part of a population. Populations of different plants and animals make a community. The communities interaction with the environment form and ecosystem, and the Earth's ecosystems make the biosphere.

• Atom- smallest unit of an element. Is made up of neutrons, protons, and electrons
  
• Molecule- is the union of at least two atoms of the same or different elements
  
• Cell- smallest functional and structural unit of all living things
  
• Tissue- group of cells with a common structure and function


• Organ-tissues functioning together for a specific task

• Organ System- several organs working together
  
• Organism- An individual, can contain organ systems
  
• Population- Organisms of the same species in a particular area
• Community- Populations interacting in a particular area

• Ecosystem- Community interacting with the physical environment
  
• Biosphere- Regions of the Earths crust, waters, and atmosphere inhabited by living things
  

2. Aquiring Materials and Energy-Humans and animals aquire these when they eat food. Nutrient molecules are the building blocks for energy and are provided by food. These molecules are broken down completely for energy or converted into motion.

3. Reproduction- All living things have parents and cells can come into being only from preexisting cells. By reproducing, they create a copy of themselves to ensure the continuance of their own kind. They are able to make more of themselves through DNA. DNA is replicated to ensure exact copies of genes are passed to the offspring.
Metabolism- all the chemical reactions in the cell
DNA- contains the hereditary material that directs the structure of the cell and its metabolism Genes- direct developement makes sure the organism resembles parents

4. Growing and Developing- All organisms undergo development and growth is a part of development. Development in humans includes all the changes from the time the egg is fertilized until death

5. Being Homeostatic- Homeostasis is an internal environment maintained by the organ systems
6. Responding to Stimuli- Movement in humans is dependent on the nervous and muscoskelatal systems

7. Life Has an Evolutionary History- Organisms share the same characteristics of life because their ancestory can be traced to the first cell(s). They are diverse due to adapting to different ways of life. This explains the unity and diversity of life .

Humans are Related to Other Animals
Living things are classified into three domain

• Eukarya- have membrane- bounded nucleus. Humans are in this domain
  


• Archea



• Bacteria

The domain Eukarya contains four kingdoms

• Animalia-Humans and vertebrates (they have a nerve chord that is protected by a vertebral column. the repeating units of the vertebrea indicate we are segmented.) We are classified as mammals and are distinguished by highly developed brains, creative language, upright stance, and ability to use many different tools
  
• Plantae


• Fungi


• Protista

Along with a biological heritage, humans have a cultural heritage that is passed on from one generation to the next outside of biological heritage.
Humans are also members of the biosphere as are all living things on earth, however humans modify the ecosystems for our own purposes. Almost all natural ecosystems are altered by human activities which reduces biodiversity. Estimates state that we lose around 400 species per day to extinction due to human activities.

Science as a Process
Science is a way of knowing about the natural world. Scientific theories are concepts that tell us about the patterns in the natural world, and how they are organized. The Scientific Method is made up of certain steps

• Observation
  
• Hypothesis


• Experiment with observations


• Conclusion


• Scientific theory

Making Sense of a Scientific Study
The type of data given to support scientific data is very important. Anecdotal data (testemonials) is not reliable. Statistical data is accompanied by the standard error which tells how uncertain a particular value is.

Science and Social Responsibility
Science, technology and society have interacted throughout human history, and are accordingly affected by human values. Every person should be aware of science and participate in decisions made, because they will affect all of us.


Chapter Two Chemistry of Life

From Atoms to Molecules
Matter is anything that has mass and takes up space. An element is the basic building block for matter.Most of the human body is made up of just carbon, nitrogen, oxygen,and hydrogen. Even so, there are other elements that are extremely important to our health The atom is the smallest unit of an element that retains the chemical and physical properties of the element. When atoms bond together they form molecules. When different atoms come together they are called compounds
There are two different types of bonds:

• Ionic- carry either a positive or negative charge (NaCl)



• Covalent- atoms share electrons (H20)

Water and Living Things
Water is the most abundant molecule in living organisms accounting for 60-70 percent of weight. The properties of water make life possible. Ions and molecules that interact with water are hydrophilic. If they don't interact they are hydrophobic.
Acids dissociate in water, releasing hydrogen ions. Bases take up hydrogen ions or release hydroxide ions.
In living things, the body fluids must be maintained within a certain range or health suffers.


Molecules of Life
There are four catagories of organic molecules that are unique to cells

carbohydrates

• lipids
  


• proteins



• nucleic acids
  Each type is composed of subunits. When the cell constructs this macromolecule, it uses a dehydration reaction. To breakdown macromolecules the cell uses a hydrolysis reaction, adding the components of water

Carbohydrates
H-C-OH, they function for quick and short term energy storage

Simple carbohydrates

• monosaccharide- 3-7 carbon atoms
  


• pentose- 5 carbon sugar
  


• hexose- 6 carbon sugar
  


• glucose-the hexose we use as an immediate energy source.
  


• disaccaride- joining 2 monosaccarides together by dehydration reaction

Complex carbohydrates (polysaccarides):macromolecules that contain many glucose units

• starch
  


• glycogen
  


• cellulose
  

Lipids
Contain more energy per gram than other biological molecules

• Fats
  


• Oils
  


• Tryglyceride
  


• Fatty Acid- carbon hydrogen chain ending in COOH these are either saturated or unsaturated
  


• Dietary fat-
  


• Phospholipids- constructed like fats, but the third fatty acid is replaced with a phosphate group
  


• Steroids

Proteins
Have a primary importance in function and structure of cells

• Support- structural proteins that make up nails, hair, collagen



• Enzymes-speed chemical reactions
  


• Transport- channel and carrier proteins allow substances to enter and exit cells(hemoglobin is a complex protein that transports oxygen)
  


• Defense-antibodies (combine with antigens and prevent destruction to cells)
  


• Hormones- regulatory proteins
  


• Motion- allow parts of cells to move and cause muscles to contract

Proteins have amino acid sub units. The amino acids differ according to their R group. Proteins are unable to function unless they have their usual shape. Denaturation is an irreversible change in shape.
The structure of a protein has at least three levels

• primary structure- linear sequence of amino acids joined by peptide bases
  
• secondary structure- polypeptide takes a certain orientation in space
  
• tertiary structure- three dimensional shape

Nucleic Acids
DNA and RNA- they are called nucleic acids, because they first appeared in nucleus of cells
DNA- stores genetic information and replicates adn transmits this information when a cell or organism reproduces. Four bases in DNA

• adenine


• thymine- replaced by uracil in RNA
  
• quanine
  
• cytosine

RNA- an intermediary that conveys the instructions from DNA regarding the amino acid sequence in a protein.
Nucleotides have metabolic functions. By adding 3 phosphate groups, adensosine is modified to create ATP which is an energy carrier in cells. The last two bonds are easily broken leaving ADP

Chapter Three Cell Structure and Function

What is a Cell
Most cell can be seen only under a microscope and are abou 100 micrometers in diameter.
The Cell Theory:

• a cell is the basic unit of life- there is no smaller unit of life than a cell


• all living things are made up of cells
  
• new cells arise only from preexisting cells-parents pass of copy of their genes to their offspring

The small size of cells is explained by the surface area to volume ratio. The volume represents the needs of the cell

How Cells are Organized
Human cells have a plasma membrane, cytoplasm(contains all the organelles) and a nucleus

Plasma Membrane and How Substances Cross it
The plasma membrane marks the boundary between the outside and inside of the cell. The function of the membrane is vital to cell survival.
The plasma membrane is a phospholipid bylayer with proteins that are either attatched or embedded. It is selectively permeable by allowing only certain molecules and ions to enter and exit freely.(such as oxygen and carbon dioxide)

• Diffusion is the random movement of molecules from the area of higher concentration until there is equal distribution. No cellular energy is used
  
• Osmosis is the diffusion of water across a plasma membrane
  
  


• Facilitated Transport is when a molecule is transported at a rate higher than usual across the plasma membrane from higher to lower concentration. No cellular energy. Each protein carrier binds to only one particular molecule



• Active transport- moving opposite normal direction.. lower to higher. Requires cellular energy, pumps



• Endocytosis- phagocytosis, pinocytosis
  


• Exocytosis

The Nucleus and Production of Proteins
The nucleus stores genetic information. Every cell in the body contains the same genes, but each type of cell has certain genes turned on or off. Proteins help determine a cells specificity.
Chromatin coils into chromosomes that contain a DNA molecule and associated proteins.
Ribosomes are composed of proteins and rRNA and this is where protein synthesis occurs. They occur in the cytoplasm or attatched to the endoplasmic reticulum.
The endoplasmic reticulum has a rough ER and smooth ER. From the rough ER proteins are synthesized to enter the interior where processing and modification begin
The golgi apparatus modifies the proteins before secretion occurs.
Lysosomes are produced by the golgi apparatus and are found in all cells of the body,


The Cytoskelaton and Cell Movement
The cytoskelaton is several types of protein fibers criss crossed throughout the cytoplasm. This helps maintain the shape of the cell and either anchor or help move the organelles. Microtubules are cylinders that contain 13 rows of protein called tubulin. During cell division microtubules form spindle fibers, that in turn assist the movement of chromosomes.
Cilia and flagella grow from basal bodies which are structured like centrioles by containing microtubules and they utilize ATP energy to move


Mitochondria and Cellular Metabolism
Mitochondria are the powerhouse of the cell. They have there own genes and reproduce themselves. They convert the chemical energy of glucose products into chemical energy of ATP molecules
The process of producing ATP is called cellular respiration. This is an important component of metabolism. The metabolic pathways involved in breaking down glucose allow the energy in a glucose molecule to release slowly, producing ATP gradually. The three pathways are

• Glycolisis-sugar splitting
  


• Citric Acid Cycle- produces 2 ATP per glucose molecule
  


• Electron transport chain- energy that is released from electrons passing from carrier to carrier is used for ATP production. This process requires oxygen
  Each cell produces ATP in the mitochondria. The ATP is used for the metabolic work of the cell, such as muscle contraction, nerve impulses



• Fermentation is an anaerobic process that produces 2 ATP molecules per glucose molecule

Chapter Four Organization and Regulation of Body Systems

Types of Tissues
A tissue is composed of specialized cells of the same type and they perform a common function in the body. There are four major types

• Connective
  


• Muscular
  


• Nervous
  


• Epithelial
  

Connective Tissue Connects and Supports
All types have three components, specialized cells, ground substance, and protein fibers. There are three types of connective tissue

• Fibrous- loose or dense. Contain fibroblast cells. Loose tissue protects and encloses internal organs. Dense tissue is found in tendons and ligaments
  


• Supportive-Hyaline cartilage, elastic cartilage and fibrocartilage
  


• Bone-the most rigid connective tissue. Compact or Spongy



• Fluid- bathes the body's cells and removes CO2 and other wastes. Red blood cells, white blood cells, platelets, lymph

Muscular Tissue Moves the Body

• Skelatal muscle- voluntary muscle. Attatched by tendons to the bones. They are striated
  


• Smooth muscle- visceral. No striations, involuntary, found in walls of internal organs and blood vessels
  


• Cardiac muscle- only in the walls of the heart. Its contraction accounts for the heartbeat

Nervous Tissue Communicates
This tissue consists of nerve cells (neurons) and the neuroglia that support the neurons

• Neurons- specialized cell made up of dendrites, cell body, axon. Found in the brain, spinal cord and nerves



• Neuroglia- support neurons and in the brain engulf cellular and bacterial debris

Epithelial Tissue Protects
Epithelium are tightly packed cells that form a continuous layer. Can also perform secretion, absorption, excretion and filtration

• Simple Epithelia- one layer of cells. Three types : Squamous, Cuboidal, Columnar
  


• Pseudostratified Columnar Epithelium- appears to be layered, but true layer do not exist (lining of the windpipe)
  


• Transitional Epithelium- tissue changes in response to tension (lining of urinary bladder)
  


• Stratified Etpithelia- layers of cells (nose, mouth, esophagus)



• Glandular Epithelia- secretes a product. Exocrine and Endocrine glands

Cell Junctions
Cell junctions help tissue perform its particular function

• Tight junctions
  


• Adhesion junctions
  


• Gap junctions

Integumentary System
Type of organ system. The skin has many functions, including to regulate the body temperature giving it a significant role in homeostasis. The skin has two regions

• Epidermis- made of stratified squamous epithelium
  


• Dermis- dense fibrous connective tissue beneath the epidermis. Contains collagen and elastic fiber



• Subcutaneous - beneath the dermis and not a part of the skin. Composed of loose connective tissue

Organ Systems
All of these systems play a part in homeostasis and assist in the functioning of not only their system, but others as well

• Integumentary
  


• Cardiovascular



• Lymphatic and Immune
  


• Digestive
  


• Respiratory
  


• Skelatal
  


• Muscular
  


• Nervous
  


• Endocrine
  


• Reproductive
  

Homeostasis
This is the body's ability to maintain a relative constancy of its internal environment by adjusting its physiological processes. The nervous and endocrine systems play a very important role by coordinationg the activities of all the other organ systems to maintain homeostasis.
Negative feedback is present when the output of the system dampens the original stimulus
Positive feedback is a mechanism that brings and even greater change in the same direction.

Links for pictures used

1 . http://www.biologycorner.com/bio/DNA.html

2. http://www.eblaforum.org.library.science/

3. http://www.biology.lsu.edu/introbio/

4. http://www.chemistryland.com./links/ionicI.gif

5. http://www.cem.msu.edu/~reusch/virtTxtJm/images/lewstrc1.gif

6. http://www.about.com/d/biology/1/0/H/1/nucleus.jpg

7. http://www.uic.edu/classes/bios/bio100/lectfo3am/epithelial.jpg

8. http://fig.cox.miami.edu/~cmallery/150/physiol/homeostasis.jpg

9. http://images.medicinenet.com/images/illustrations/skin.jpg



Works Cited

1. Frolich Power Point


2. Mader, Sylvia. Human Biology 10th edition. Pages 1-81