CELL HISTORY, STRUCTURE AND FUNCTION

CELL HISTORY, STRUCTURE AND FUNCTION

The cell is the smallest unit of life that can carry out life processes.

Chapter 4

Robert Hooke 1665 -observed cork through a light microscope. Anton Van Leewenhoek 1675 -observed LIVING cells. Matthias Schleiden 1838 plants are made of cells. Theodor Schwann 1839 animals are made of cells

! Used an early compound microscope to look at a thin slice of cork. Named these little chambers he saw in the plant material cells because they reminded him of monks cells. 1 square inch of cork contained 1,259,712,000 chambers!!

"#$ %! Sent reports to London s Royal Society with drawings and facts on anything he examined: bread mold, bee s stinger, blood cells, teeth, hair, his own saliva, excrement and semen! He reported finding animalcules - in actuality these were protozoa. 1683- discovered bacteria Claimed there were 8,280,000 in a single drop of semen!!

&' ()(! Concluded all plants are made up of cells Part of the duo that proposed the Cell Theory

'$ ()*! Concluded that ALL living matter in cellular, but it was not until the 1860s, with the help of the work of Louis Pasteur, was it widely excepted that life cannot spontaneously arise, but must come from pre-existing cells. Second part of the duo that founded the Cell Theory.

All living organisms are made of one or more cells Cells are the basic units of structure and function Cells come only from pre-existing cells

+$,, --,. A. Anton van Leeuwenhoek B. Robert Hooke C. Matthias Schleiden D. Rudolf Virchow

$,''$ // 0 A. All plants are made of cells. B. All animals are made of cells. C. Plants and animals have specialized cells. D. All plants and animals are made of cells.

+,,$1- -,. A. Cells are the basic units of life. B. All living things are made of cells. C. Very few cells reproduce. D. All cells are produced by existing cells.

--0 A. Bacteria B. Plants and animals. C. Multicellular organisms. D. All of the above.

$2-,3 PROKARYOTIC EUKARYOTIC

Prokaryoticcells that do not have a nucleus and internal membranebound structures Most unicellular organisms are prokaryotes. Bacteria

4 Eukaryotic-Cells that do have a nucleus and internal membrane-bound structures. Most multicellular organisms are eukaryotes. Yeast and algae (unicellular, eukaryotes) Plant and animal

5 0 A. Cytoplasm B. A cell membrane C. Nucleus D. Genetic material

+,,$. A. Prokaryotes B. Bacteria C. Eukaryotes D. Organelles

4 0 A. A nucleus B. Specialized organelles C. Genetic material D. All of the above

+,,$ / -. A. Plants B. Animals C. Bacteria D. All of the above

6 //3 Cytoplasm Gel like material that protects, supports and suspends organelles.

6 //3 Cell membrane Semi-permeable allows some materials in and keeps others out. This helps to maintain cellular homeostasis.

',5/&/ Phospholipid Bilayer -2 layers of phospholipids. Phospholipid- phosphate head attached to two lipids (fatty acid tails). Polar phosphate group allows membrane to interact with its environment. Fatty acid tails create a waterinsoluble layer in the middle which is non-polar. Fluid mosaic model - membrane is flexible Cholesterol -keeps fatty acid tails from sticking together Transport proteins -allow needed substances to move through the membrane

Chapter 4 5,

1 Command center Surrounded by a nuclear envelope Contains genetic material: chromatin chromosomes Nucleolus-makes ribosomes Ribosomes-site where proteins are made Can be found floating in the cytoplasm or attached to endoplasmic reticulum

4 Series of folded membranes allow a large amount of work to be done in a small amount of space Transportation unit for the cell Rough Endoplasmic Reticulum (RER) Ribosomes attached Protein synthesis Smooth Endoplasmic Reticulum (SER) Produce and store lipids

7"-- # Flattened tubular membranes Packaging plant Modify, sort, package, and transport proteins throughout the cell

! Storage sacs Temporary storage of materials Store food, enzymes, waste Plant cells have one large vacuole. Animal cells have many small vesicles.

8''&4' Contain digestive enzymes Digest excess or worn organelles, food particles, viruses, and bacteria Surrounded by membrane that prevents it from destroying the cell Can burst causing cell death

Chapter 4 & Cellular respiration -converts food into energy Cell Powerhouse Number of mitochondria depends upon the function of the cell Ex: muscles cells have more mitochondria than fat cells

59 -/, Examples: Chloroplast Located in plant cells, some bacteria, and protists. Capture light energy to produce and store food Contain chlorophyll-green pigment that traps light energy

--,5 Plants Only!! Stores food and pigment Provide the green color of leaves Important with photosynthesis

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5 Other Plastids: All store food and pigment Leucoplasts: stores starch Appear white under the microscope Example: potato, turnip

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Chromoplasts: stores pigments Ex. Red and orange colors in tomatoes

Cytoskeleton tiny fibers that give structure and support to the cell. Microfilament- thin and tubular support the cell membrane. Microtubule- thick and tubular also branched. Act as rails on which materials move through the cell.

& Microtubules: Hollow tubes made of proteins Assist with movement for one-celled organisms

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&,/ Microfilaments: Also assist with movement Ex. Responsible for muscle cells contractions

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6 Aid in movement and feeding Composed of microtubules Cilia-short, numerous hair-like projections that move in a wavelike motion Flagella-long, whip-like projections

$ Rigid outer covering PLANT CELLS Located outside the cell membrane Provides support and protection

Plant Cell Animal Cell

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5"/ Animal Cell vs. Plant cell Animal Cell DO NOT contain a cell wall or plastids. Plant Cell DO contain a cell wall, plastids, and a large central vacuole.