Lesson 2: Eukaroytic Cells and Organelles Flashcards
The Nucleus
-Almost all cells have one
-Normally the largest organelle
-Surrounded by 2 membranes (Nuclear Envelope)
-Small gaps called Nuclear Pores
-Contains chromosomes
-Sight of Transcription (First stage of protein synthesis)
The RER
-Have ribosomes attached to them
-Usually continuous with the Nuclear Envelope
-Where most protein synthesis takes place
The SER
-Don’t have ribosomes attached to them
-Creates lipids and steroids
The Golgi Apparatus
-Stack of curves membranes enclosing flattens sacs
-Not a stable structure
-Where proteins are packaged and processed changing into the required product
-Some products are in vesicles that bud off from the GA to the plasma membrane
-Vesicles then fuse with membrane and deposit the proteins outside the cell (Exocytosis)
Ribosomes
-Tiny organelles
-Bound to RER
-Not membrane bound
-Site of protein synthesis
-Acts as an assembly line for coded information (mRNA) from the nucleus to make proteins from amino acids
Mitochondria
-Surrounded by a double membrane known as an envelope
-Site of aerobic respiration
- Makes the cells ATP
-Each cell makes its own ATP
-cells that use more energy have more mitochondria
-Inner membrane is called a Cristae where ATP is made
-Inside called the matrix is the site of the stages of aerobic respiration called the Krebs Cycle
Lysosomes
-Specialised Decretory Vesicles
-Contain proteins that act as digestive enzymes
-Fuse with other vesicles that contain something that needs to be digested
-Destroy unwanted organelles
Chloroplasts
-Site of photosynthesis
-Double membranes called an envelope (isolate reactions from the rest of cell)
-Inside are membranes called grana that contain chlorophyll
-Light energy used to make ATP and reduced NADP
-ATP and NADP are used to make carbohydrates
-Often contain starch grains to be stored
Plasma Membrane
-Cover surface of every cell
-Surround most organelles
-Allow movement in and out of cell
-One of main components is phospholipids
Intrinsic and extinct proteins allow movement in and out of cell
Centrioles
-Found in animal cells
-Make and organise structures called microtubules
-Microtubules are responsible for moving chromosomes around the cell during cell division
The Cytoskeleton
-All plant and animal cells contain a network of microfilaments that act as a skeleton helping support of the cell and its shape
-Together with microtubules they create the cytoskeleton
-Provides mechanical strength to the cell
-Can help the whole cell move
The Cell Wall
-Always surround plant cells
-Not an organelle
-Outside the plasma membrane
-Provides strength and support
-Maintuans cell shape
-Permeable and allow solutions to pass through
-Fungi have cell walls that contain chitin not cellulose
Cilia and Flagella
-Long thin extensions from the surface of a cell which can produce movement
-Cilia are relatively short and are found in large numbers
-Flagella are longer and going in ones it twos
Vacuoles
-Surrounded by a membrane called the Tonoplast and contains liquid
-Only plants have them
-Filled with water and solutes which maintains cell stability
-When pushed against cell wall makes cell turgid
-If all cells are turgid helps to support the plant especially non woody plants
