Membrane-bound Organelles Flashcards
What eight things do all eukaryotic cells contain?
Nucleus Nucleolus Cytoplasm Cytoskeleton Plasma membrane Membrane bound organelles Small vesicles Ribosomes
What is the cytoskeleton?
A network of protein filaments that act as a transport system for organelles.
They also cause the contraction of muscle cells
What produces ribosomes?
The nucleolus
How do organelles allow the cell to work efficiently?
Shared labour
Describe the structure of the nucleus
Double membrane
Nuclear envelope with contains pores
Nucleolus containing RNA
What are the main functions of the nucleus?
Provides instructions for protein synthesis
Stores organism’s genomes
Transmits genetic information
Nucleolus separates contents of nucleus from the rest of the cell
Describe the structure of rough endoplasmic reticulum.
System of membranes containing fluid filled cavities
Coated with ribosomes
What are the functions of RER?
Intracellular transport system
Provides a large surface area for ribosomes
Describe the structure of smooth endoplasmic reticulum
System of membranes containing fluid filled cavities
No ribosomes on its surface making it smooth
What are the functions of SER?
Contains enzymes that catalyse reactions involved in the metabolism of lipids
Involved in absorption, synthesis and transport of lipids in the gut
The enzymes in SER catalyse what?
Synthesis of cholesterol
Synthesis of lipids/phospholipids
Synthesis of steroid hormones
Describe the structure of the Golgi apparatus.
Stacks of membrane bound flattened sacs
What are the two functions of the Golgi apparatus?
Modification of proteins
Packaging of proteins
How can proteins be modified in the Golgi apparatus?
Addition of sugar molecules to form glycoproteins
Addition of lipid molecules to form lipoproteins
Fold them into their 3D structure
Describe the structure of the mitochondria.
Spherical, rod shaped or branched
Surrounded by two membranes with a fluid filled matrix
How long are mitochondria usually?
2-5 micrometers
What are the mitochondria the site of?
ATP production during aerobic respiration
How long are chloroplast?
4-10 micrometers
We’re are chloroplasts only found?
In plant cells
Describe the structure of chloroplasts.
Double membrane bound with a fluid filled matrix
What do chloroplasts contain loops and grans of?
DNA and starch
What is the membrane called on a vesicle?
Tonoplast
What is the purpose of a vacuole?
Maintains cell stability
Why are vacuole only found in plants?
They maintain turgidity which is usually only important in plants
Describe the structure of lysosomes.
Small bags formed from the Golgi apparatus
Single membrane
Contain powerful hydrolytic (digestive) enzymes
What is the purpose of lysosomes?
To keep the hydrolytic enzymes separate from the rest of the cell
Can engulf old organelles or foreign matter
What is the purpose of cilia and undulipodia?
Beat and move the band of mucus in the airways
One cilia acts as an antenna (receptor) for cell signalling
What is the structure of cilia?
Protrusions from the cell surrounded by the plasma membrane
Each contains microtubules
