Eukaryotic Cells

Eukaryotic Cell

What is the structure of the Lysosome?

Spherical sacs surrounded by a single membrane

What is the function of the Lysosome?

• Contains and releases hydrolytic enzymes
  
  

• Hydrolyses (digests) worn-out organelles, dead cells (autolysis), or pathogens engulfed by phagocytes.

What is the structure of the Golgi Apparatus?

• A stack of membrane-bound, fluid-filled, flattened sacks called cisternae.
  
  

• Golgi vesicles pinch off at the end of cisternae

What is the function of the Golgi Apparatus?

• Modifies and packages proteins and lipids
  
  

• Adds carbohydrates to proteins to form glycoproteins
  
  

• Produces secretory enzymes and forms lysosomes
  
  

• Transports finished products out of the cell or to the cell surface membrane in Golgi vesicles.

What is the structure of the Cell membrane?

Made of a phospholipid bilayer containing proteins

What is the function of the cell membrane?

Controls the exchange of substances between the internal and external environments of a cell

What is the structure of the Smooth Endoplasmic Reticulum?

A network of flattened sacks (cisternae) is smooth, as it does not have ribosomes on its surface

What is the function of the Smooth Endoplasmic Reticulum?

Synthesises and stores lipids and carbohydrates.

What is the structure of the Rough Endoplasmic reticulum?

A network of flattened sacks (cisternae), rough, as its surface is covered by ribosomes

Whats is the function of the Rough Endoplasmic reticulum?

• Provides a large surface area for the synthesis of proteins and glycoproteins.
  
  

• Transports proteins through the cell towards the Golgi apparatus.

What is the structure of the mitochondria?

• Surrounded by a double membrane
  
  

• Inner membrane folds to form cristae, and this provides a large surface area
  
  

• Contains a fluid-filled matrix; the matrix contains DNA and 70S ribosomes for protein synthesis

What is the function of the mitochondria?

• Site of aerobic respiration
  
  

• Produces ATP molecules (immediate energy source for cell)
  
  

• Contains DNA to code for enzymes needed in respiration
  
  
  

What is the structure of the Nucleus?

• Surrounded by two membranes called the nuclear envelope
  
  

• Contains a nucleolus – produces RNA and makes ribosomes

• Contains nuclear pores

What is the function of the nucleus?

• Contains the genetic code
  
  

• Site of DNA replication and transcription (making mRNA)

What is the structure of the permanent vacuole?

• Surrounded by a single membrane called the tonoplast, and this is filled with cell sap
  
  

• Temporary store of amino acids and sugars

What is the function of the permanent vacuole?

Contains cell sap, which helps keep the cell turgid (plant cell that is swollen, firm)

What is the structure of the cell wall?

• Made of the Microfibrils of the cellulose polymer (plants and algae)
  
  

• Made of the polysaccharide chitin (fungi)

What is the function of the cell wall?

• Provides structural strength
  
  

• Prevents cell bursting from pressure (when water enters by osmosis)

What is the structure of chloroplasts?

• Surrounded by a double membrane
  
  

• Contains fluid-filled sacks called thylakoids, which stack up to form grana
  
  

• Grana are connected by thin membranes called lamellae
  
  

• Stroma is a fluid-filled matrix surrounding the grana
  
  

• Also contains circular DNA, 70S ribosomes, and stored starch grains

What is the function of chloroplasts?

• Site of photosynthesis
  
  

• Thylakoid membranes/grana: Provide a large surface area for the light-dependent reaction.
  
  

• Stroma contains enzymes required for photosynthesis in the light-independent reactions

What is the structure of ribosomes?

• Made of 2 sub units of protein and rRNA
  
  

• 80s - Larger, found in eukaryotic cells
  
  

• 70s - Smaller, found in prokaryotic cells, mitochondria and chloroplasts
  
  

What is the function of ribosomes?

Site of protein synthesis