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a fluid phospholipid bilayer embedded with proteins and glycoproteins. It contains glycolipids as well as complex lipids called sterols
semipermeable membrane that determines what goes in and out of the cell
the cytoplasmic mebrane
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Algae, fungi, and plant cells have this; animal cells and protozoans lack this
helps the cell resist osmotic lysis
the cell wall
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ompartmentalizes the cell for various different but interrelated cellular functions. It consists of the nucleus, the endoplasmic reticulum, and the Golgi complex
the endomembrane system
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separated from the cytoplasm by a nuclear envelope
where assembly of ribosomal subunits occurs
where DNA is located
the nucleus
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a maze of parallel membranous tubules and flattened sacs surrounding the nucleus that connects with the nuclear membrane and runs throughout the cytoplasm
the endoplasmic reticulum
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involved in protein synthesis, production of new membrane, modification of newly formed proteins, and transport of these proteins and membrane to other locations within the cell.
rough ER
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contains enzymes for lipid biosynthesis, especially the synthesis of phospholipids and steroids
also forms transition vesicles to transfer molecules produced in the rough ER to the Golgi complex
smooth ER
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consists of 3-20 flattened and stacked saclike structures called cisternae. A complex network of tubules and vesicles is located at the edges of the cisternae
functions to sort proteins and lipids received from the ER, modify certain proteins and glycoproteins, and sort and package these molecules into vesicles for transport to other parts of the cell or secretion from the cell.
the golgi complex
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rod-shaped structures ranging from 2 to 8 micrometers in length surrounded by two membranes
located throughout the cytoplasm
function during aerobic respiration to produce ATP through oxidative phosphorylation
have their own DNA and ribosomes
mitochondria
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disk-shaped structures ranging from 5 to 10 micrometers in length
surrounded by an inner and an outer membrane
carry out photosynthesis, the process of converting light energy to chemical energy stored in the bonds of sugar
have their own DNA and ribosomes
chloroplasts
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synthesized by the endoplasmic reticulum and the the Golgi complex
membrane-enclosed spheres typically about 500 nanometers in diameter that contain powerful digestive enzymes that function to digest materials that enter by endocytosis
lysosomes
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membrane-bound organelles containing an assortment of enzymes that catalyze a variety of metabolic reactions
peroxisomes
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cylindrical complexes that use ATP to digest proteins into peptides and play a critical role in enabling the body to kill infected cells and cancer cells during adaptive immunity
proteasomes
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large membranous sacs, one is smaller in size
often used to store materials used for energy production such as starch, fat, or glycogen
also transport materials within the cell and form around particles that enter by endocytosis.
vacuoles and vesicles
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composed of rRNA and protein and consist of 2 subunits
both attached to the endoplasmic reticulum and free in the cytoplasm
serve as a workbench for protein synthesis
ribosomes
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a network of microfilaments, intermediate filaments, and microtubules
functions include - giving shape to cells lacking a cell wall, allowing for cell movement, enabling movement of organelles within the cell, endocytosis, and cell division
cytoskeleton
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two organelles that function in locomotion
consist of 9 fused pairs of protein microtubules with side arms of the motor molecule dynein that originate from a centriole. These form a ring around an inner central pair of microtubules that arise from a plate near the cell surface. This complex of microtubules is surrounded by a sheath continuous with the cytoplasmic membrane
flagella + cilia
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theory states that mitochondria and chlopoplasts in today's eukaryotic cells were once prokaryotic microbes
endosymbiotic theory
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4 pieces of evidence for endosymbiotic theory
1. Chloroplasts are the same size as prokaryotic cells, divide by binary fission, and, like bacteria, have Fts proteins at their division plane. The mitochondria are the same size as prokaryotic cells, divide by binary fission, and the mitochondria of some protists have Fts homologs at their division plane.
2. Mitochondria and chloroplasts have their own DNA that is circular, not linear.
3. Mitochondria and chloroplasts have their own ribosomes that have 30S and 50S subunits, not 40S and 60S.
4. Several more primitive eukaryotic microbes, such as Giardia and Trichomonas have a nuclear membrane but no mitochondria.
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