Plastids (Chloroplast)

• They are in Plants and Algae

• Helps photosynthesis-combines energy from light with water ad carbon dioxide to form sugars, which is the source of energy for plants.

-Parts of Chloroplast

• Stroma-thick substance in between the grana. Contains molecules of DNA, has ribosomes
• Grana(Granum)-Stacks of Thylakoids
• Has two phospholipid membranes, Inner, outer
• Thylakoids-where photosynthesis takes place. Has proteins and pigments that absorb light such as chlorophyll, chloro-green. They add surface area to grana to help absorb more light.

   

 

Mitochondria

• Described as the powerhouse of the cell due to it creating the ATP(adenosine triphosphate) which provides energy for the cell
• There distinct areas in it
  • Outer membrane, encases organelle is made up of proteins and phospholipids
  • Intermembrane space, gap between the inner membrane and outer membrane
  • Inner Membrane, Has ATP Synthase, helps make ATP, has cristae, increases surface area, by wrinkling inner membrane, which enables more ATP to be produced.
  • Matrix, enclosed by inner membrane, important in ATP production it is helped by ATP synthase

 

 

 

Cytoskelaton

• Provides the shape and structure of the cell
• Protects the Cell
• Allows for motion in the cell
• Plays a role in intercellular transport, for example, vesicles which carry cellular products and waste.
• MTOC (microtubule-organization center)
  • is found in all plant and animal cells
  • Is a centrosome, controls the maturation of the cell
  • During Interphase (a cell making organelles and copying DNA) an animal cell has one near the nucleus
  • Is the source of microtubules which are involved in the transport of molecules

 

• Is made of insanely thin filiments

 

Extracellular Fluid

• Made of intersitial fluid and blood plasma
• Has glucose which is regulated by homeostasis
• The pH is regulated by buffers (around 7.4)
• Typical volume is around 15 liters

 

Nuclear Membrane

• Is a double membrane Has an inner and outer membrane. Both are a lipid bilayer, the outer is connected with the rough endoplasmic reticulum
  • the space between the membranes is called the perinuclear space
• Separates stuff in the nucleus (especially DNA)  from the cytoplasm
• Has ribosomes binded to the outside
• There are pores for the movement of materials such as proteins and RNA

 

Endoplasmic Reticulum

• Is a network of tubules-small tube, vesicles, and cisternae-membrane disks
• It is held together by the cytoskeleton
• Responsible for transporting proteins that are used in the cell membrane
• Rough Endoplasmic Reticulum, lined with ribosomes giving it rough look
  • creates lysosomes and secreted proteins
• Smooth Endoplasmic Reticulum, involved in making of lipids, and drug detoxification, storage of enzymes and other substances especially calcium ions
  • It is connecetd to the nuclear envelope
• Sacroplasmic Reticulum
  • special type of smooth ER and is found in muscles.
  • Stores calcium

 

 

 

 

Golgi Apparatus

• Made of sacs of cisternae(normally around 5-8)
• It processes packages and secretes macromolecules made by the cell so that the cell can use the substances for other processes. After it secretes the macromolecules it sends them throughout the cell
• It is involved in the transport of lipids

 

 

 

 

 

Ribosome

• Help put single amino acids into polypeptide chains. Called protein translation. To do this they read messenger RNAs, they are like genetic blueprints for protein synthesis.
• They are made of RNA strands and proteins
• They are found in the cytoplasm and they are also found on the rough endoplasmic reticulum

 

 

 

 

 

Plasma Membrane

• is a semipermeable membrane-lets only some particles and molecules through. Let’s stuff in by the process of diffusion, how fast this process goes depends on pressure, concentration, and temperature.
• It is a phospholipid bilayer
• It is mostly made of lipids and proteins
• attaches the cytoskeleton and the cell wall

 

 

 

 

 

 

 

 

 

Endomembrane System

• Found only in eukaryotic(animal) cells not prokaryotes(plants)
• Divides the organelles in the cell
• Allows for movement of molecules in the cell
• The membranes that make up this system are a lipid bilayer
• This system acts as a surface for the synthesis of proteins and lipids
• Is made up by: cell membrane, nuclear envelope, endoplasmic reticulum, golgi apparatus, lysosomes, vacuoles, and vesicles

 

 

 

 

 

Exocytosis

• Is where cells direct secratory vesicles to the cells membrane. A secratory vesicle is a vesicle with soluble proteins, membrane proteins and lipids. they are sent to th cell membrane an release their sontents into the membrane and also the extracellular fluid.
• Exocytosis is needed to produce enzymes, hormones and antibodies
• It plays an important role in cellular signalling
  • This process converts electrical signals going through cell into chemical information with the involvement of neurotransmitters

 

Vacuole

• They are foud in plant cells and some animal cells
• Th surrounding membrane is called the tonoplast
• the liquid inside is called the cell sap, it is made of water and enzymes
• Their basic funcctions are:
  • Get rid of structural debris
  • isolate harmful material
  • contain waste substances and remove them from the cell
  • maintain the pressure and also the pH (usually acidic) of the cell
  • let the cell change shape
• The pressure of the cell is maintained throuh the process of osmosis. Water diffuses into the vacuole putting pressure on the cell wall.
  • This pressure also pushes the chloroplast up against the cell wall enabling for more energy intake
  • If the pressure decreases eneough the cell will plasmolyse

 

 

Lysosome

• contain digestive enzymes (acid hydrolases)
• the things they digest include
  • organelles that no longer work
  • food molecules
  • and viruses ad bacteria that have been consumed by the cell
• the digestive enzymes are held i by the membrane. this is important because it keeps the enzymes from destroying the cell
• they are createdby the golgi apparatus
• lysosomes fuse with vacuoles and the lysosome inserts its enzymes to digest the waste and molecules in the vacuole
• there is an acidic pH inside the lysosome that is different form the slightly basic pH of the cystol
  • the acidic pH is kept due to proton pumps in the membrane that take in H+ ions