* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Cell Structure and Function
Survey
Document related concepts
Tissue engineering wikipedia , lookup
Cytoplasmic streaming wikipedia , lookup
Cell encapsulation wikipedia , lookup
Extracellular matrix wikipedia , lookup
Cell culture wikipedia , lookup
Signal transduction wikipedia , lookup
Cell growth wikipedia , lookup
Cellular differentiation wikipedia , lookup
Cell membrane wikipedia , lookup
Organ-on-a-chip wikipedia , lookup
Cytokinesis wikipedia , lookup
Cell nucleus wikipedia , lookup
Transcript
Cell Structure and Function Chapter 7.1 & 7.2 • Hooke was the first person to see a cell under a microscope (1665). – He named the cork cells after the cells (rooms of his monastery). The Cell Theory • All living things are made of cells. • Cells are the basic units of structure and function in living things. • New cells are produced from existing cells. Types of Cells • All cells are surrounded by a membrane and carry biological information (DNA). • Cells are categorized based on whether or not they contain a nucleus. – (Nucleus [nuclei, pl]: a large membraneenclosed structure that contains the cells’ genetic material in the form of DNA.) • Eukaryotes are cells that contain a nucleus. • Prokaryotes are cells that do not contain nuclei. Eukaryotes • Karyon: greek – kernal or nucleus • Eu: greek – true • Where is genetic material contained? – In a membrane bound organelle (nucleus) • Types of Organelles – Dozens of highly specialized structures and internal membranes • Size – Many 2-1000µm in size • How old – Evolved 1.5 billion years ago. • Types of Organisms (examples) – Plants, animals, fungi, and protists Prokaryotes • Karyon: greek – kernal or nucleus • Pro: greek – before • Where is genetic material contained? – Not in a nucleus • Types of Organelles – None • Size – Most 1-10µm in size • How old – Evolved 3.5 billion years ago • Types of Organisms (examples) – bacteria Eukaryotic Cell Structure • Organelles: the specialized structures inside a cell. • Cytoplasm: the portion of the cell outside the nucleus. • Cell membrane: a lipid bilayer that surrounds all cells. • Cell wall: provides support and structure to plant, algae, fungi, and many prokaryotes. – Lies outside the cell membrane. Nucleus • The nucleus controls most cell processes and contains the hereditary information of DNA. • The nucleus is surrounded by a nuclear envelope that is composed of two membranes. – Proteins, RNA, and other molecules can move to and from the rest of the cell through nuclear pores. • Chromatin is the material inside the nucleus. – It is DNA bound to proteins. – Chromatin condenses to form chromosomes during cell division. • Nucleolus is where ribosomes begin to assemble. Ribosomes • Ribosomes are small particles of RNA and protein found throughout the cytoplasm. • Proteins are assembled on ribosomes. • The nucleus gives coded instructions to the ribosomes, so they know what proteins to build. Endoplasmic Reticulum (ER) • An internal membrane system. • The ER assembles the lipids that go into building the cell membrane. • The ER also synthesizes proteins for export from the cell. • There are two types of ER. – Rough ER: has ribosomes on its surface. • Newly made proteins leave the ribosomes and the RER chemically modifies them. – Smooth ER: doesn’t have ribosomes on its surface. • Enzymes on the SER synthesize membrane lipids and detoxify drugs. (Liver Cells have lots of SER.) Golgi Apparatus • After proteins leave the RER, the Golgi apparatus modifies, sorts, and packages the proteins. • After the proteins are in the Golgi apparatus, they are ready to be – stored inside the cell – or secreted outside of the cell. Lysosomes • Lysosomes are the cleanup crew of a cell. • Lysosomes are small, enzyme filled organelles. • They digest (breakdown) lipids, carbohydrates, and proteins that the rest of the cell can use. • They also break down organelles that are damaged or not used anylonger. Vacuoles • A saclike structure that stores materials such as – Water – Salts – Proteins – Carbohydrates • Plants have large central vacuoles filled with liquid. • Animals have smaller storage vacuoles. Mitochondria • Mitochondria are organelles that convert the chemical energy stored in food into compounds that are more convenient for the cell to use. • Mitochondria are made up of two membranes. • In humans, all of our mitochondria come from our moms. • Contain some DNA. Chloroplast • Chloroplasts are organelles that capture the energy from sunlight and convert it into chemical energy in a process called photosynthesis. • Chloroplasts are surrounded by two membranes. • Only plants and a few other organisms have chloroplasts. • Contain some DNA. Cytoskeleton • A network of protein filaments that helps the cell to maintain its shape. • It also is involved in cellular movement.