Cell Biology - 1.1

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Cell Theory

1. All living things are composed of cells
2. The cell is the Basic unit of life
3. Cells only come from preexisting cells

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7 functions of life:

1. Nutrition
2. Metabolism
3. Growth
4. Response to Stimuli
5. Excretion
6. Homeostasis
7. Reproduction

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Nutrition (as a function of life)

The process by which living things take in materials from its environment for growth and repair

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Metabolism (as a function of life)

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Chemical reactions inside the cell, including cell respiration to release energy

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Growth (as a function of life)

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Cells increase in size over time. When they are large enough and acquire the materials required they may divide

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Response (as a function of life)

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The ability to react to changes in the environment. Receptors in the plasma membrane detect molecules in the environment and send signals to the internal machinery of the cell

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Excretion (as a function of life)

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The process by which living things remove waste products produced by the cell’s activities

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Homeostasis (as a function of life)

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Cells maintain a stable internal environment by carrying out a continuous series of chemical reactions

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Reproduction (as a function of life)

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Producing offspring either sexually or asexually

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Why is the SA to V ratio of a cell important in the limitation of a cell size

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If a cell grew infinitely large it would reach a point where this balance between SA and V become imbalanced, meaning it used substances more quickly than it could obtain them. At this point cellular activity decrease and/or ceases.

What arises from the interaction of component parts of a cell?

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Emergent properties, help living organisms better adapt to their environments and increase their chances of survival.

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How can it be that all of an organism’s cells have the same genetic information, but the cells have a wide variety of shapes and functions?

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All cells are coded, meaning each cell has genes that are expressed, or ‘turned on’ and ‘turned off’. This is because that certain types of cells only require certain genes to create the proteins relevant to that cell.

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What are key properties of a stem cell?

\-undifferentiated (not specialized) \n -ability to self-renew \n -ability to give rise to various types of cell

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Two types of stem cells:

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Adult and Embryonic

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Adult Stem Cells

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\-Found in adult tissue (e.g. neural cells, cardiac muscle, bone marrow) \n -Can self-renew many times (but limited) \n -Multipotent (only give rise to become cells in the tissue they came from)

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Embryonic Stem Cells

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\-Can self renew forever \n -Come from the blastocyst stage of an embryo \n -Pluripotent (can give rise to become almost anything in body)

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Totipotent Cells

A potency of a stem cell that allows it to differentiate into absolutely everything include supporting structures of pregnancy

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Multipotent Cells

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A potency of a stem cell that allows it only to differentiate into the cells from their tissue of origin

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Pluripotent Cells

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A potency of a stem cell that allows it to differentiate into almost every cell, excluding supporting structures of pregnancy

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What factors make striated muscle cells an exception to the cell theory?

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\-each cell is much larger than most animal cells \n -each cell has many nuclei

What factors make Giant algae an exception to the cell theory?

\-Does not have cross walls or septa, and so forms an uninterrupted tube-like structure \n -Many nuclei spread along tube

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Difference in nutrition between Paramecium and Chlamydomonas

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Ingests small organisms and digests through vesicals VS contains chloroplast and thereby produces own nutrition

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Difference in Growth between Paramecium and Chlamydomonas

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Nutrients from digestion are used for energy and materials needed for growth VS able to grow through the absorption of minerals and photosynthesis

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Difference in Response between Paramecium and Chlamydomonas

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Cilia helps the cell to move, cells moves toward or away from external stimuli VS has an eyespot that allows it to detect the brightest light and therefore it moves towards the light stimuli

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Difference in Excretion between Paramecium and Chlamydomonas

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Waste products in both cells are expelled outside through diffusion

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Difference in Homeostasis between Paramecium and Chlamydomonas

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Both have contractile vacuoles which fill with water and expels it through plasma membrane, maintaining water levels constant

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What is Stargardt’s Disease

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A genetic disease that results from a recessive mutation of a gene that effects photo receptor cells in retina

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How can Stargardt’s disease be treated by stem cells?

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Stem cells developed into retina cells which are injected into the eye. These healthy retina cells then attach to retina and remain, increasing quality of vision

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Procedure in treating Stargardt’s disease with Stem cells

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1. skin taken from patients arm and used to make stem cells (to avoid rejection)
2. Cocktail of proteins and vitamins are used to coax stem cells into growing healthy retina cells.
3. Healthy retina cells injected into back of patients eye, restoring sight

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How is Stem cell therapy used to treat Leukemia?

1. Leukemia starts by leukocytes growing and functioning abnormally and are unable to fight infection 2. Chemotherapy used to kill bad leukocytes and allow body to grow healthy ones
2. If chemotherapy is unsuccessful, the bone marrow killed by chemotherapy is replaced with healthy stem cells

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What are the ethical considerations associated with the therapeutic use of ESCs? (Embryonic Stem Cells)

\-Technology used could also be used for reproductive cloning \n -Creation of stem cell line requires destruction of a human embryo \n -embryos are a human life, and thus have the same rights of an individual \n -Saving or enhancing the quality of life of an individual doesn’t justify the destruction of the life of another \n -ESC research has not produced viable long term treatment whereas adult stem cells have

Formula for Magnification:

Magnification = Image size / Actual size

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Formula for Actual size

Actual size = Image size / Magnification

How many Nanometres in a Meter?

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10 to power of 9

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How many Micrometres in a Meter?

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10 to power of 6

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Atypical Cells

\-Straighten muscle tissue composed of repeated units of sacomeres that show striped patterns \n - Muscle cell is multi-nucleated

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Aseptate Fungal Hypae

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* Long threads with many nuclei

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Viruses

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* Non living entities, no property outside cell, no cellular structure-but the do have protein coats of DNA or RNA

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Flagella

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Movement of Chalmydomnas

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Chalmydomnas

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Unicellular green algae over the world in soil, water, oceans and mountains

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Villi

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Folds up SA when exposed to digestive food

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Celiac Disease

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disorder where immune system destroys the villi - in small intestine which causes gluten issues

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Parkinson Diease

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Parkinson’s disease is caused by a loss of nerve cells in the part of the brain called the substantia nigra. Nerve cells in this part of the brain are responsible for producing a chemical called dopamine.

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Paramecium

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genus of single-celled ciliated organisms.

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Stargardt’s disease

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a degenerative eye disease that has been the target of stem cell research.

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70S

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the size of prokaryotic ribosomes.

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80S

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the size of eukaryotic ribosomes.

Archaea

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a domain of prokaryotes.