Cells

 

1. Robert Hooke (1665)

2.  Anton van Leeuwenhoek

3.  prokaryotic---

·        cells that do not have a nucleus

·        lack membrane-bound organelles

·        in most cases unicellular; in rare cases, multicellular

·        circular DNA

·        bacteria

4. eukaryotic---

·        cells that have a nucleus

·        linear DNA

·        animals, plants, protista, and some unicellular organisms

5. autotrophic---producers---an organism that makes or synthesizes its own food using photosynthesis

6. heterotrophic---consumers---organisms that cannot make their own energy-rich molecules; they obtain energy by eating other organisms

 

7. Equation for Photosynthesis

 

sunlight (energy)  +  6CO2   +  6H2O     ®     C6H12O6   +  6O2

 

 

8.  Equation for Cellular Respiration

 

C6H12O6   +  6O2  ®     energy   +  6CO2   +  6H2O    

 

Organisms use oxygen to get energy from food, some of which is released as heat.

If cellular respiration stopped, a cell would not have the energy it needs to perform its functions.

 

 

 

 

 

 

 

 

 

 

Plant and Animal Cells---

Structures---

Function--

cell membrane

·     thin, flexible outer covering of a cell

·      controls what enters and leaves the cell

·     nutrients and water enter and wastes leave the cell through the cell membrane

cytoplasm

·     thick, gel-like fluid

·     “cell-liquid”

·     cell organelles float in the cytoplasm

nucleus (nuclei)

·     control center; “brain”

·     contains the cell’s genetic material; DNA, chromosomes, traits

·     chromosomes---genetic information of organisms

nuclear membrane

·     surrounds the nucleus

·     thin structure that separates the nucleus from the rest of the cell

vacuole

·     used for storage

·     plant cells usually have one large vacuole that stores water and other substances

·     vacuoles help support the plant

·     animal cells have smaller vacuoles that contain either food or wastes

·     vacuoles in animals cells can be temporary

mitochondria (mitochondrion)

·     small organelles that break down sugar and release energy

·     “powerhouse” or energy source of the cell

·     process by which mitochondria release energy from sugar is called cellular respiration

·     makes ATP (Adenosine triphosphate)---compound that cells use to store and release energy

endoplasmic reticulum

·     series of rough and smooth membranes that move materials around the cell

·     proteins enter ER to be transported to other parts of the cell

Golgi body

·     packages proteins and carbohydrates for export from the cell

·     “post office”

ribosomes

·     synthesizes proteins for cell’s activities

·     some float freely while others are attached to ER

cell wall

·     ONLY IN PLANTS

·     rigid structure that surrounds the cell membrane

·     supports plant cells and gives them their shape

·     mostly made of cellulose

chloroplast

·     ONLY IN PLANTS

·     plant cell structure in which photosynthesis takes place

·     contain chlorophyll---a green pigment that absorbs light

·     chlorophyll---captures radiant energy from sunlight

lysosomes

·     contains digestive enzymes that help break down nutrients for the cell

nucleolus

·     inside the nucleus and contains RNA (ribonucleic acid)

centrioles

·     helps organize cell division

 

 

 

Types of Cells---

blood

·     in a liquid called plasma

·     bone marrow

·     RBC---receive oxygen from respiratory systems

·     WBC---increase due to infections
bone

·     produce molecules (usually proteins) that communicate with other cells

nerve

·     long and thin

·     carry and receive messages around the body
muscle

·     movement

 

Organization:

organelles  ® cells  ®    tissue  ®   organ  ®   organism

A tissue is a group of similar cells working together to perform a specific function.

 

Types of Tissues---

epithelial tissue

·  closely packed cells that cover body surfaces and line internal structures

·  makes up the skin and the lining of the stomach
muscle tissue

·  made up of cells that are able to shorten, or contract, to move the body

·  makes up the heart (cardiac) as well as muscles attached to bones

·  found in many other parts of the body such as the stomach and blood vessels

·   contract and relax to produce movement of the body
nerve tissue

·  made of long, thin cells that carry messages around the body

·  makes up the brain and spinal cord

·  sends electrical signals through the body
connective tissue

·  made up of many kind of cells that support the body and hold it together

·  bones, fat, cartilage, and blood

·   joins, supports, protects, insulates, nourishes, and

    cushions organs

 

 

 

 

 

 

 

Plant and Animal Cells Grow and Divide:

 

 

 

Use of single-celled organisms in industry, in the production of food, and impacts on life---

1. The fuel industry is now looking at using algae in biofuel production.

2.  Sewage-disposal facilities are aided by bacteria in the breakdown of many waste products (not only organic) and in the neutralization of some of the toxic substances that make their way into sewage.

3.  Bacteria play an important role in the biological view of pest control—as the natural enemies of different organisms that damage food crops and the agricultural industry.

4.  Several bacteria play a major role in modern genetic-engineering techniques: by inserting specific genes into the bacterial cell, the bacteria can be induced to produce the protein which these genes encode. These proteins can then be used to produce medicines and other vital substances, such as hormones. (using bacteria with recombinant DNA used in the production of human growth hormone or insulin)

5.  Another use of bacteria is in the making of food, especially dairy products. Special fermentation bacteria convert milk to products such as cheese, cultured milk and yogurt, the manufacture of which would be impossible without them.     

6.  Many are helpful and serve useful functions such as causing breads to rise, fermenting sugars to alcohol, and decaying organic matter to replenish nutrients in the soil. 

7.  Bacteria are responsible for much food spoilage, and for disease (pathogenic bacteria), but they are also made use of, for example in the pickling process and fermentation of milk, as well as in the manufacture of vitamins and amino acids and a variety of enzymes and hormones.
8.  Antibiotics are produced by a number of micro organisms and inhibit the growth of other micro organisms even at very low concentrations. As such, the antibiotics have found wide application in chemotherapy, plant pathology, food preservation, veterinary medicine and as research tools in biochemistry and molecular biology. At present about 7000 antibiotics are known and about 100 of these are produced commercially by microbial fermentation process. Fungi, bacteria and actinomycetes are important antibiotic producing organisms. Most species of Streptomyces are quite active in the production of a variety of antibiotics.