Bilogy
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Transcript of Bilogy
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Eukaryotic Cell Parts
Organelles
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Organelles compartmentalize functions within
the cell.
Organelles Include -NucleusRibosomesMitochondria and ChloroplastsEndoplasmic Reticulum Golgi apparatusLysosomes and Peroxisomes
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Nucleus The nucleus is a
membrane bound structure that contains the cell's hereditary information and controls the cell's growth and reproduction.
It is commonly the most prominent organelle in the cell
http://biology.about.com/library/weekly/aa032300a.htm
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Nucleus- The nucleus is the control center of the cell. It is the largest organelle in the cell and it contains the DNA of the cell. The DNA of all cells is made up of chromosomes. DNA (Deoxyribonucleic Acid) contains all the information for cells to live, perform their functions and reproduce.
Inside the nucleus is another organelle called the nucleolus. The nucleolus is responsible for making ribosomes.The circles on the surface of the nucleus are the nuclear pores. These are where ribosomes, and other materials move in and out of the cell.
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The nucleus and the nuclear envelope
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RibosomesProtein synthesis occurs at tiny organelles called ribosomes.
Ribosomes are composed of a large subunit and a small subunit.
Ribosomes can be found alone in the cytoplasm, in groups called polyribosomes, or attached to the endoplasmic reticulum.
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Energy-Related Organelles
The two energy-related organelles of eukaryotes
are chloroplasts and mitochondria. Both organelles house energy in the form of ATP.
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Mitochondria Mitochondria are found both in plant and animal
cells. It is Rod/sausage shaped & relatively large
(1 μm – 5μm in size). Mitochondria are bounded by a double
membrane surrounding fluid-filled matrix. The outer controls the entry & exit of materialsInner has many folds called cristae
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The matrix contains enzymes that break
down carbohydrates and the cristae house
protein complexes that produce ATP. Contain their own genome (distinct from
nuclear genome) Self-replicating
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Functions of Mitochondria
Site of aerobic respiration
(Krebs cycle & oxidative phosphorylation)Responsible for the production of energy rich
ATP moleculesThe numbers of mitochondria reflect the
metabolic activity of the cell – so large
numbers are found in muscle and liver cells.
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Chloroplast- The cell organelle in which photosynthesis takes place. In this organelle the light energy of the sun is converted into chemical energy. Chloroplasts are found only in plant cells not animal cells. The chemical energy that is produced by chloroplasts is finally used to make carbohydrates like starch, that get stored in the plant. Chloroplasts contain tiny pigments called chlorophylls. Chlorophylls are responsible for trapping the light energy from the sun.
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Photosynthesis is the conversion of light energy into chemical energy by living organisms. The raw materials are carbon dioxide and water; the energy source is sunlight; and the end-products are oxygen and (energy rich) carbohydrates, for example sucrose and starch.
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Plants make their own food in their leaves by a process called photosynthesis.
Carbon dioxide + Water Glucose + Oxygen
Animals cannot make their own food, and hence, they rely on plants, and/or other animals for their source of food.
sunlight
Chlorophyll
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Photosynthesis is a process in which green plants use energy from the sun to transform water, carbon dioxide, and minerals into oxygen and organic compounds. It is one example of how people and plants are dependent on each other in sustaining life. Photosynthesis happens when water is absorbed by the roots of green plants and is carried to the leaves, and carbon dioxide is obtained from air that enters the leaves and diffuses to the cells containing chlorophyll. The green pigment chlorophyll is uniquely capable of converting the active energy of light into a latent form that can be stored (in food) and used when needed.
Photosynthesis provides us with most of the oxygen we need in order to breathe. We, in turn, exhale the carbon dioxide needed by plants. Plants are also crucial to human life because we rely on them as a source of food for ourselves and for the animals that we eat.
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Endoplasmic reticulum (ER)- It is a network of membranes throughout the cytoplasm of the cell. There are two types of ER.
When ribosomes are attached it is called rough ER and smooth ER when there are no ribosomes attached.
The rough endoplasmic reticulum is where most protein synthesis occurs in the cell. The function of the smooth endoplasmic reticulum is to synthesize lipids in the cell. The smooth ER is also helps in the detoxification of harmful substances in the cell.
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The Golgi apparatus
The Golgi apparatus consists of a stack of curved saccules.
The Golgi apparatus receives protein and also lipid-filled vesicles from the ER, packages, processes, and distributes them within the cell.
This organelle may also be involved in secretion.
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FUNCTION
Assembling glycoproteins (such as mucin) by combining
carbohydrate and proteinTransporting and storing lipidsFormation of lysosomesProducing digestive enzymesSecretes carbohydrates which are used in the formation of
plant cell walls and in insect cuticles
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Lysosomes and vacuoles
Lysosomes are vesicles produced by the Golgi apparatus.
Lysosomes contain hydrolytic enzymes and are involved in intracellular digestion.
Vacuoles (large) and vesicles (small) are membranous sacs in the cell that store substances.
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Lysosomes Lysosomes are vesicles produced by the
Golgi apparatus. Lysosomes contain hydrolytic enzymes
and are involved in intracellular digestion.
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Peroxisomes
Peroxisomes are vesicles that contain enzymes.
The enzymes in these organelles use up oxygen and produce hydrogen peroxide.
Peroxisomes are abundant in the liver where they produce bile salts and cholesterol and break down fats.