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Cell Structure Review. Eukaryotic Cells. Have a nucleus Found in multi-cellular organisms & some unicellular organisms. Prokaryotic Cells. Do not have a nucleus Found in bacteria. Cell Membrane. Thin, flexible layer Separates the cell from its surrounding environment
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Eukaryotic Cells • Have a nucleus • Found in multi-cellular organisms & some unicellular organisms
Prokaryotic Cells • Do not have a nucleus • Found in bacteria
Cell Membrane • Thin, flexible layer • Separates the cell from its surrounding environment • Controls movement of materials into and out of the cell • Helps maintain the cell’s internal environment
Chromatin • Coils of DNA and protein that form chromosomes. • Can be thought of as chromosomes without shape. • Granular-like material found in the nucleus containing genetic information
Chromosome • Worm-like / rod-like structures formed from chromatin during cell reproduction. • They become distinct during the reproductive part of the cell cycle as the cell divides. • Composed of DNA
Cytoplasm • Thick, jelly-like substance contained within the cell membrane • Most of the work of the cell is carried out here. • The majority of the organelles are suspended in the cytoplasm.
DNA • The genetic material found in all living cells. • Contains the information needed for an organism to grow, maintain itself, and reproduce • Stands for deoxyribonucleic acid
Endoplasmic Reticulum • Network of channels/tubes leading from the nuclear membrane into the cytoplasm • Helps transport materials between the nucleus and the cytoplasm • Also involved in transporting proteins • Two types: - Smooth E.R. = no ribosomes -Rough E.R. = contains ribosomes
Golgi Bodies • Serve as storage and packaging centers. • Look like stacks of flattened sacs • Proteins made by the ribosomes are packaged into vesicles (small pockets) • These packages are used by the cell and sometimes are released from it.
Lysosomes • Sac-like structures that contain enzymes • Where digestion of cell nutrients & food molecules take place • Breaks down cellular waste or things that are harmful to the cell • Similar to the job of white blood cells
Mitochondria • Organelles that cause the release of energy by using oxygen to break down sugars. • Usually round or tube shaped • Releases food molecules that supply energy to the cell; it is known as the powerhouse of the cell. • Usually more than one in a cell
Nuclear Envelope • Has a double-layered membrane that separates the nucleus from the cytoplasm. • Contains pores to help facilitate the exchange of materials between the nucleus and the cytoplasm
Nucleus • Control center of the cell • Manages all of the cell’s activities • Largest organelle • Contains the genetic material (chromatin) the cell needs to reproduce and function. • Is surrounded by the nuclear envelope and also contains the nucleolus and chromatin.
Ribosomes • Sites of protein manufacturing in the cell • Assemble proteins that: • Create chemical messages to run a cell. • Build cell organelles • Line the membrane of the rough endoplasmic reticulum & are found in the cytoplasm