Micro Final review notes.
Chapter 9.
Section 1.
- Cells are the basic units of structure and function in living things. (Cells form the parts of an organism and carry out all of an organism’s processes, or functions.)
- The invention of the microscope make it possible for people to discover and learn about cells.
- A microscope is an instrument that makes small objects look larger. A light microscope that has more than one lens is called a compound scope.
- Robert Hooke was the first one to observe cells with his compound scope.
- Schleiden: all plants are made of cells. Schwann: all animals are made of cells. All living things are made up of cells. Virchow: all cells come from cells.
- Cell theory: 1. All living things are composed of cells. 2. Cells are the basic units of structure and function in living things. 3. All cells are produced from other cells.
- Magnifying lenses in light microscopes magnify an object by bending the light that passes through them. A lens with this curved shape is called a convex lens.
- The ability to clearly distinguish the individual parts of an object is called resolution.
- Electron microscopes use a beam of electrons instead of light to produce a magnified image.
section 2
- Organelles, carry out specific functions within the cell.
- A plant’s cell wall helps to protect and support the cell. Made mostly of a strong material called cellulose.
- The cell membrane controls what substances come in and out of a cell.
- Nucleus is the control center, directing all of the cell’s activities.
- Nuclear envelope protects the nucleus.
- Materials pass in and out of the nucleus through pores in the nuclear envelope.
- Chromatin contains genetic material.
- Nucleolus makes ribosomes.
- Ribosomes functions as factories to produce proteins.
- Cytoplasm, gel like fluid in cells containing many organelles.
- Mitochondria are known as ‘power houses’ of the cell because they convert energy in food molecules to energy the cell can use to carry out its functions.
- Endoplasmic reticulum’s passageways carry proteins and other materials from one part of the cell to another.
- Golgi body receive proteins and other newly formed materials from the endoplasmic reticulum, package them, and distribute them to other parts of the cell.
- Chloroplasts capture energy form sunlight and use it to produce food for the cell.
- Vacuoles are the storage areas of cells. Can also store waste products.
- Lysosomes are small round structures containing chemicals that break down certain materials in the cell.
- In many-celled organisms, cells are often organized into tissues, organs, and organ systems.
- A tissue is a group of similar cells that work together to perform a specific function.
- An organ is made of different kinds of tissues that function together.
- An organ system is a group of organs that work together to perform a major function.
- While a bacterial cell does have a cell wall and a cell membrane, it does not contain a nucleus. The bacterial cell’s genetic material , which looks like a thick tangled string, is found in the cytoplasm.
Section 3.
- An element is any substance that cannot be broken down into simpler substances.
- The smallest unit of an element is called an atom. An element is made up of only one kind of atom.
- When two or more elements combine chemically, they form a compound.
- Some important groups of organic compounds found in living things are carbohydrates, lipids, proteins and nucleic acids.
- Compounds don’t contain the element carbon are called inorganic compounds. Water and sodium chloride or table salt are familiar examples of inorganic compounds.
- A carbohydrate is an energy rich organic compound made of the elements carbon, hydrogen and oxygen. Sugar and starches are examples of carbohydrates.
- The cellulose found in the cell walls of plants is a type of carbohydrates.
- Lipids are energy rich organic compounds made of carbon, hydrogen and oxygen. Contain more energy than carbohydrates. Cell membranes are made mainly of lipids.
- Proteins are large organic molecules made of carbon, hydrogen, oxygen and nitrogen, and in some cases, sulfur.
- Protein molecules are made up of smaller molecules called amino acids.
- Much of the structure of cells is make up of proteins.
- Enzyme is a type of protein that speeds up a chemical reaction in a living thing. Without enzymes, many chemical reactions that are necessary for life would either take too long or not occur at all.
- Nucleic acids are very long organic molecules make of carbon, oxygen, hydrogen, nitrogen and phosphorus. It contain the instructions that cells need to carry out all the functions of life.
- DNA, is the genetic material that carries information about an organism and is passed from parent to offspring. Directs all of the cell’s functions. Most found in chromatin.
- RNA, plays an important role in the production of protein. Found in the cytoplasm and the nucleus.
- Water makes up about two thirds of our body.
- Most chemical reactions within cells could not take place without water.
- Water can also help cells keep their size and shape; it also keeps the temperature of cells from changing rapidly.
Section 4.
- The cell membrane is selectively permeable.
- Substances can move into and out of the cell do so by one of three methods: diffusion, osmosis or active transport.
- Diffusion is the main method by which small molecules move across the cell membrane. Diffusion is the process by which molecules move from an area of higher concentration to an area of lower concentration.
- The concentration of a substance is the amount of the substance in a given volume.
- Collisions cause molecules to push away form one another.
- Osmosis is the diffusion of water molecules through a selectively permeable membrane. Because cells cannot function properly without adequate water, many cellular processes depend on osmosis.
- The movement of dissolved materials through a cell membrane without using cellular energy is called passive transport.
- Diffusion and osmosis is passive transport.
- Active transport is the movement of materials through a cell membrane using cellular energy.
- The cell membrane surrounds and engulfs a particle then form a vacuole within the cell. This is another way of active transport.
Chapter 10.
Section 1
- The process by which a cell captures energy in sunlight and uses it to make food is called photosynthesis.
- Nearly all living things obtain energy either directly or indirectly form the energy of sunlight captured during photosynthesis.
- An organism that makes its own food is called an autotroph.
- An organism that cannot make its own food is called a heterotroph.
- During photosynthesis, plants and some other organisms use energy form the sun to convert carbon dioxide and water into oxygen and sugars.
- Stage 1. Capturing the energy in sunlight. Occurs mostly in leaves.
- Pigments, colored chemical compounds that absorb light.
- The main photosynthetic pigment in chloroplasts is chlorophyll.
- Stage 2. The cell uses the captured energy to produce sugars. Needs water and carbon dioxide for this stage.
- Carbon dioxide enters the plant through small openings on the undersides of the leaves called stomata.
- The photosynthesis equation.
Section 2
- Respiration is the process by which cells obtain energy form glucose. During respiration, cells break down simple food molecules such as sugar and release the release the energy they contain.
- Stage 1. Molecules of glucose are broken down into smaller molecules in cytoplasm.
- Stage 2. Small molecules are broken down into smaller molecules in mitochondria.
- Fermentation provides energy for cells without using oxygen.
- Alcoholic fermentation. Important to bakers and brewers. The carbon dioxide produced by yeast creates air pockets in bread dough.
- Lactic acid fermentation, when lactic acid builds up, you feel a painful sensation in you muscles.
Section 2.
- The regular sequence of growth and division that cells undergo is known as the cell cycle.
- Three main stages, inter phase, mitosis and cytokinesis
- During interphase, the cell grows, makes a copy of its DNA (replication) and prepares to divide into two cells.
- During mitosis, one copy of the DNA is distributed into each of the two daughter cells.
- The double rod structure is called chromosomes, each chromosome has 2 rods because the cell’s DNA has replicated. Each identical rod in a chromosome is called a chromatid.
- The two chromatids are held together by a structure called a centromere.
- Prophase: Chromatin in the nucleus condenses to form chromosomes. The pairs of centrioles move to opposite sides of the nucleus. Spindle fibers form a bridge between the ends of the cell. The nuclear envelope breaks down.
- Metaphase: The chromosomes line up across the center of the cell. Each chromosomes attaches to a spindle fiber at its centromere.
- Anaphase: The centromeres split. The two chromatids separate. One chromatid is drawn by its spindle fiber to one end of the cell. The other chromatid moves to the opposite end. The cell stretches out as the opposite ends are pushed apart.
- Telophase: The chromosomes begin to stretch out and lose their rodlike appearance. A new newclear envelope forms around each region of chromosomes.
- Cytokinesis: The cell membrane pinches in around the middle of the cell. The cell splits in two. Each daughter cell ends up with an identical set of chromosomes and about half the organells.
- Cytokinesis is somewhat different in plant cells. A structure called cell plate forms across the middle of the cell. The cell plate gradually develops into new cell membranes between the two daughter cells. New cell walls then form around the cell membranes.
- Nitrogen bases are molecules that contain the element nitrogen and other elements. DNA has four kinds of nitrogen bases: adenine thymine guanine and cytosine. A matches T. G matches C
- Because of the way in which the nitrogen bases pair with one another, the order of bases in each new DNA molecule exactly matches the order in the original DNA molecule.
Section 4
- Cancer is a disease in which cells grow and divide uncontrollably, damaging the parts of body around them.
- Cancers are often named by the place in the body where they begin.
- Leading cause of death in US
- Cancer begins when mutation disrupt the normal cell cycle, causing the cell to divide in an uncontrolled way.
- A tumor is a mass of abnormal cells that develops when cancerous cells divide and grow uncontrollably
- Tumors often take years to grow to a noticeable size. Some of the cancerous cells may break off the tumor and enter the bloodstream. In this way. The cancer can spread to other areas of the body.
- There are tree common ways to treat cancer: surgery, radiation, and drugs that destroy the cancer cells.
- Chemotherapy is the use of drugs to treat a disease.
- Cancer treatment drugs are carried throughout the body by the bloodstream. These drugs kill cancer cells or slow their growth.
- Preventing cancer: avoiding smoking, eating a healthful diet, protecting their skin from bright sunlight.
Chapter 11
Section 1
- A virus is a tiny, non-living particle that enters and then reproduces inside a living cell.
- Virus are considered non-living because viruses do not show all the characteristics essential for life. Are not made of cells, do not use its own energy to grow or respond to their surroundings.
- Although viruses can multiply, they do so differently than organisms. Viruses can multiply only when they are inside a living cell.
- A host is an organism that provides a source of energy for a virus or another organism.
- Parasite, an organism that lives on or in a host and causes it harm. Almost all viruses destroy the cells in which they multiply.
- Virus shapes: round, rod-shaped, bricks, treads, bullets, robot-like.
- A bateriophage is a virus that infects bacteria.
- One nanometer is one billionth of a meter.
- Viruses are named after the disease they cause, the organisms they infect, the place where it was first found, they scientists who first indentified it.
- All viruses have two basic parts: a protein coat that protects the virus and an inner core made of genetic material.
- Each virus contains a unique surface proteins. The shape of the surface proteins allow the virus to attach to certain cells in a host.
- A certain virus can attach only to one or a few types of cells.
- Once inside a cell, a virus’s genetic material takes over many of the cell’s functions. It instructs the cell to produce the virus’s proteins and genetic material. These proteins and genetic material then assemble into new viruses.
- Active viruses, immediately take over the cell’s functions.
- Hidden viruses, hide for a while. Its genetic material becomes part of the cell’s genetic material.
- Gene therapy, scientists add genetic material to a virus and then use the virus as a messenger service to deliver the genetic material to cells that need it.
Section 2
- Bacteria are prokaryotes. The genetic material in their cells is not contained in a nucleus.
- Has cell war, cell membrane, cytoplasm, ribosomes, genetic material and flagellum.
- Flagellum, a long, whiplike structure that helps a cell to move. A flagellum moves the cell by spinning in places like a propeller.
- Cell shapes: rodlike, spiral, spherical.
- A micrometer is one millionth of a meter.
- Bacteria must have a source of food and a way of breaking down the food to release its energy.
- Some bacteria are autotroph. Capture energy in sunlight, or live deep in mud, get energy from chemical substances in their environment to make food.
- Some bacteria are hetertrophs. Must consume other organisms or the food that other organisms make.
- Some bacteria don’t need oxygen during respiration.
- When bacteria have plenty of food, the right temperature, and other suitable conditions, they thrive and reproduce frequently.
- Binary fission, one cell divides to form two identical cells.
- Asexual production is a reproductive process that involves only one parent and produces offspring that are identical to the parent.
- Sexual reproduction involves two parents who combine their genetic material to produce a new organism, which differs from both parents.
- Conjugation, one bacterium transfers some of its genetic material into another bacterium through a thin, threadlike bridge that joins the two cells. After the transfer, the cells separate. Results in bacteria with new combinations of genetic material.
- An endospore is a small rounded thick walled resting cell that forms inside a bacterial cell. It contains the cell’s genetic material and some of the cytoplasm. They can survive for many years. When conditions are suitable, it opens up, bacterium can begin to grow and multiply.
- Bacteria are involved in oxygen and food production, environmental recycling and cleanup, and in health maintenance and medicine production.
- During pasteurization, the food is heated to a temperature that is high enough to kill most harmful bacterial without changing the taste of the food.
- Decomposer, organisms that break down large chemicals in dead organisms into small chemicals
Section 3
- Infectious diseases: illnesses that pass from one organism to another.
- Infectious diseases can spread through contact with an infected person, a contaminated object, an infected animal, or an environmental source.
- Toxin, a poison viruses produce, damage the cells.
- Many bacterial diseases can be cured with medications known as antibiotics.
- Antibiotic is a chemical that can kill bacteria without harming a person’s cells.
- Antibiotic resistance results when some bacteria are able to survive in the presence of an antibiotic.
- Common bacterial diseases: lyme disease, turberculousis, tetanus, food poisoning, strep throat.
- Unlike with bacterial diseases, there are currently no medications that can cure viral infections.
- Best treatment fore viral infections is bed rest, drink of water and eating well- balanced meals.
- Common viral diseases: Influenza, Hepatitis C, Chickenpox, Acquired immunodeficiency syndrome.
- Vaccines are important tools that help prevent the spread of infectious diseases.
- A vaccine is a substance introduced into the body to simulate the production of chemicals that destroy specific viruses or bacterial. The vaccine active the body’s natural defenses, puts the body on alert.
Section 4.
- Protists are eukaryotes that cannot be classified as animals, plants ore fungi.
- All protists live in moist surroundings.
- Most protists are uni-cellular.
- Protozoans, Animal-like protists are heterotrophs and most are able to move from place to place to obtain food. Unicellular.
- Protozoans are classified into 4 groups, based on the way they move and live.
- Protozoans with pseudopods ——amoeba.
- Pseudopods, temporary bulges of the cell. “False foot”. It enables amoeba to move and feed. Forms when cytoplasm flows toward one location and the rest of the amoeba follows.
- Contractile vacuole, a structure that collects the extra water and then expels it from the cell.
- protozoans with cilia—— paramecium.
- Cilia, hair like projections from cells that move with a wavelike motion. Ciliates use their cilia to move and obtain food.
- Pellicle, a stiff but flexible covering, surrounds a paramecium and gives it shape.
- Oral groove, funnel like indentation lined with cilia. The cilia moves water containing food into the vacuole that forms at the end of the oral groove.
- Anal pore, where wastes are expelled.
- Paramicia reproduce asexually by binary fission. Sometimes by conjugation.
- protozoans with flagella—— flagellates.
- Symbiosis, a close relationship in which at least one of the species benefits. When bother partners benefit from living together, the relationship is a type of symbiosis called mutualism.
- protozoans that are parasites. They are parasites that feed on the cells and body fluids of their hosts.
- Plantlike protists. Algae are autotrophs. Algae can be different colors.
- Diatoms are unicellular protists with beautiful glasslike cell walls.
- Dinoflagellates are unicellular algae surrounded by stiff plates that look like a suit of armor.
- Euglenoids are green unicellular algae that are found mostly in fresh water. They can be heterotrophs under certain conditions. Has an eyespot containing pigments, sensitive to sunlight and help the euglena recognize the direction of a light source.
- Fungus like protists are heterotrophs have cell walls, and use spores to reproduce. Slime molds, water molds and downy mildews.
Section 5.
- Fungi are eukaryotes that have cell walls, are heterotrophs that feed by absorbing their food, and use spores to reproduce.
- Most has cell walls. Cytoplasm, many nuclei.
- hyphae, branching, threadlike tubes that make up the bodies of multicellular fungi. Substances move quickly and freely through the hyphae.
- The fungus grow hyphae into a food source, digestive chemicals ooze form the hyphae into the food, the chemicals break down the food into small substances that can be absorbed by the hyphae.
- Some fungi feed on dead organisms. Some fungi are parasites that break down the chemicals in living organisms.
- Fungi usually reproduces by making spores. The lightweight spores are surrounded by a protective covering and can be carried easily through air or water to new sites.
- Fungi produce spores in reproductive structures called fruiting bodies.
- Fungi produce both asexually and sexually.
- Budding, no spores are produced. Instead, a small yeast cell grows from the body of parent cell somewhat similar to the way bud forms on a tree branch.
- When growing conditions become unfavorable, fungi reproduce sexually.
- Groups of fungi are named for the appearance of their reproductive structures.
- Fungi play important roles as decomposers and recyclers on Earth. Many fungi provide food for people. Some fungi cause disease while others fight disease. Still other fungi live in symbiosis with other organisms.
- Lichen consists of a fungus and either algae or autrotrophic bacteria that live together in a mutualistic relationship.
Chapter 12.
Section 1.
- Organisms that causes disease are called pathogens.
- An infectious disease is a disease that is caused by the presence of a living thing within the body. When you have an infectious disease, pathogens have gotten inside you body and caused harm.
- Pathogens makes you sick by damaging individual cells.
- The 4 major groups of human pathogens are bacteria, viruses, fungi and protists.
- Pathogens can spread though contact with either infected person, soil, food, water, a contaminated object, an infected animal.
Section 2.
- In the first line of defense, the surfaces of skin, breathing passage, mouth, and stomach function as barriers to pathogens. These barriers trap and kill most pathogens with which you com into contact.
- Inflammatory response, fluid and white blood cells leak from blood vessels into nearby tissues. The white blood cells then fight the pathogens.
- A phagocyte is a white blood cell that engulfs pathogens and destroys them by breaking them down.
- If a pathogen infection is severe enough to cause a fever, it triggers the body’s third line of defense ——the immune response.
- The cells of the immune system can distinguish between different kinds of pathogens. The immune system cells react to each kind of pathogen with a defense targeted specifically at that pathogen.
- The white blood cells that distinguish between different kinds of pathogens are called lymphocytes.
- There are 2 kinds of lymphocytes, T lymphocytes and B lymphocytes. Also called T and B cells. They work together to destroy flu viruses.
- A major function of T cells is to identify pathogens and distinguish one kind of pathogen from another.
- Antigens are molecules that the immune system recognizes either as parts of your body or as coming form outside you body.
- B cells produce a kind of protein called antibodies help destroy pathogens.
- Acquired immunodeficiency syndrome, or AIDS, is a disease caused by a virus that attacks the immune system. The virus that causes AIDS is called human immunodeficiency virus, or HIV.
- HIV is the only kind of virus know to attack the human immune system directly and destroy T cells.
- Once it invades the body, HIV enters T cells and reproduces inside them.
- There is no cure for AIDS. There’s a drug treatment allow may people with AIDS to survive much longer than those in the past.
- HIV can spread from one person to another only if body fluids from an infected person come in contact with those of an uninfected person.
Section 3.
- Immunity is the body’s ability to destroy pathogens before they can cause disease.
- Active immunity, the body has produced the antibodies that fight the disease pathogens.
- A person acquires active immunity when their own immune system produces antibodies in response to a presence of a pathogen.
- Active immunity can result from either getting the disease or being vaccinated.
- Vaccination is the process by which harmless antigens are deliberately introduced into a person’s body to produce active immunity.
- A vaccine usually consists of pathogens that have been weakened or killed but can still trigger the immune system to go into action.
- Passive immunity results when antibodies are given to a person- the person’s immune system does not make them.
- A person acquires passive immunity when the antibodies that fight the pathogen come form a source other than the person’s body.
Section 4.
- An allergy is a disorder in which the immune system is overly sensitive to a foreign substance, something not normally found in the body.
- An allergy develops in response to various foreign substances that set off a series of reactions in the body.
- Any substance that causes an allergy is called an allergen.
- Histamine is a chemical that is responsible for the symptoms of an allergy.
- Asthma is a disorder in which the respiratory passages narrow significantly. This narrowing causes the person to wheeze and become short of breath
- Insulin enables body cells to take in glucose from blood and use it for energy.
- In the condition known as diabetes, either the pancreas fail to produce enough insulin or the body’s cells fail to properly use insulin
- As a result, a person with diabetes has high levels of glucose in the blood and may even excrete glucose in the urine. The person’s body cells, however, do not have enough glucose.
- Cancer is a disease in which cells multiply uncontrollably, over and over, destroying healthy tissue in the process.
- Some substances or factors in the environment, called carcinogens, can cause cancer.
Section 5.
- The environment may contain carcinogens. To reduce the risk of cancer, carcinogens need to be removed or people need to be protected form them.
- Three important environmental carcinogens are ultraviolet light, vinyl chloride and arsenic.
- UV radiation can result skin cancer.
- , ; Vinyl chloride is manufactured material that exists as colorless gas at normal temperatures. Used to make PVC.
- Arsenic is a substance that occurs naturally in soil and rock. Used to pressure treat woods.