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Cytoplasmic Organelles. September 19 th , 2012. What are Cytoplasmic Organelles?. Membrane-bound organelles within the cytoplasm of a cell Organelles include: -Nucleus -Vacuole -Vesicles -Endoplasmic reticulum -Golgi Complex -Lysosomes -Mitochondria -Chloroplasts. What is a Vacuole?.
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Cytoplasmic Organelles September 19th, 2012
What are Cytoplasmic Organelles? • Membrane-bound organelles within the cytoplasm of a cell • Organelles include: -Nucleus -Vacuole -Vesicles -Endoplasmic reticulum -Golgi Complex -Lysosomes -Mitochondria -Chloroplasts
What is a Vacuole? • Vacuoles are little pockets in the cytoplasm of a cell where a cell stores food • Found mainly in plants – they are smaller in animals • Plant cells store starch molecules and water in vacuoles • Vacuoles help keep plant cells rigid and full • Membrane surrounding vacuole is called tonoplast
Vesicles – Travel Cellular Highways • Vesicles are found in both plant and animal cells • Primary role is to transport materials throughout the cell and keep the different areas of the cell in contact
Ribosomes • Not considered to be classic organelles • Ribosomes are small particles that manufacture proteins • They connect one amino acid to another in order to create a long chain which will become a protein. This process is called protein synthesis • They are located on the endoplasmic reticulum or they are free-floating within the cytoplasm
Endoplasmic Reticulum: The Packaging System • Network of membranes throughout the cell • Two types: Rough Endoplasmic Reticulum (RER) and Smooth Endoplasmic Reticulum (SER) • Rough Endoplasmic Reticulum: Has ribosomes attached to it. Important for the synthesis and packaging of proteins • Smooth Endoplasmic Reticulum: No ribosomes attached. Stores ions and makes lipids (particularly phospholipids and steroids)
Golgi Apparatus: Delivery System • The golgi apparatus’s main function is to receive, modify and transport proteins made by the endoplasmic reticulum • Most of the transport vesicles that leave the endoplasmic reticulum (ER), specifically rough ER, are transported to the Golgi apparatus, where they are modified, sorted and shipped towards their final destination • Produce lysosomes • Structure: Made of flattened membranous structures
Lysosomes: Little Digestion Machines • Lysosomesare made in the Golgi Apparatus and the endoplasmic reticulum • They hold enzymes created by the cell and help to digest food • Float around in the cytoplasm until they are needed – they go to work when the cell absorbs or eats some food • Help break down old organelles for organelle recycling! • Tay-Sachs disease
What is the Mitochondria? • The mitochondria is the cell’s power producers • Function: Converts energy into forms that are usable by the cell • Responsible for cellular respiration: using energy (ex: glucose) to make ATP. Carbon dioxide is produced as a result • Surrounded by a double membrane (each is a phospholipid bilayer)
Mitochondria, continued… • The mitochondria consists of two membranes – outer membrane and inner membrane • The outer membrane is smooth • The inner membrane is folded into cristae(studded with proteins) and contains a liquid solution called the matrix
Chloroplasts: Show me the Green! • Chloroplast is only found in plants and some protists • Food producers of the cell convert the energy of sunlight to make sugars and starches (carbohydrates) by the process of photosynthesis • Chloroplasts have a double membrane • Chloroplasts contain chlorophyll: absorbs energy from the sun. Gives plants their green color.
Cytoskeleton • The cytoskeleton is a cellular skeleton within the cytoplasm made up of protein • The cytoskeleton helps animal and plant cells to maintain their shape and it also plays a role in intracellular transport
Cilia & Flagella • Cilia and Flagella are part of the cytoskeleton and they extend from the surface of the cell • Whiplike structures • Function: help to move liquid past the surface of the cell • They are both made of fine protein fibres • Flagella (less abundant) are long, cilia (more abundant) are short
Symbiosis Two organisms living together. Where one organism benefits from the other. • Example of symbiosis Clown fish and anemone
Endosymbiotic Theory • Argues that the mitochondria and chloroplasts were once free-living bacteria that were taken inside by another cell as endosymbionts • Evidence: both can reproduce on their own, contain their own DNA and ribosomes and they are about the same size as bacteria