2.4Eukaryotic Cell Structure Flashcards
What is the smallest molecule out of water , glucose molecule, protein and ribosome
Water
Glucose molecule
Protein
Ribosome
What’s the cytoplasm composed of in a prokaryote cell
Cytosol made of water salts and organic molecules
What does the dna in nucleus control
The metabolic activities of the cell and the synthesis of proteins
What are nuclear pores
They are contained within the nuclear envelope which dna is also contained within
Nuclear pores allow molecules to move into and out of the nucleus
What is the nucleolus and what’s it composed of
Area within nucleus and responsible for producing ribosomes
Composed of proteins and RNA
What are mitochondria
Site of the final stage of cellular respiration
Where the energy stored is made available for the cell to use
Number of mitochondria is reflected by how much energy the cell uses
What is the structure of a mitochondria
It has a double membrane
Inner membrane is highly folded to form Cristae - here enzymes used in respiration is contained
The fluid interior is called the matrix
What are vesicles and what’s there structure
Membranous sacs that have storage and transport roles to cells
Consists of a single membrane with fluid inside
What are lysosomes
Specialised forms of vesicles that contain hydrolytic enzymes
Responsible for breaking down waste material in cells
Important role in immune system as they break down pathogens ingested by phagocytic cells
What are the components of the cytoskeleton
Microfilaments
Microtubules
Intermediate fibres
Centrioles
What are microfilaments
Contractile fibres grimes from the protein actin
Responsible for cell movement and contraction during cytokinesis
What is cytokinesis
Process in which cytoplasm of a single E cell is divided to form 2 daughter cells
What are microtubules
They are scaffold like structures that determine the shape of the cell they are like this due to globular Tubulidentata proteins polymerising
What are composed in microtubules
Spindle fibres
These have a role in physical segregation of chromosomes in cell division
What are intermediate fibres
Give mechanical strength to cells and help maintain their inegrity
What are centrioles
Composed of microtubules
2 of them form a centrosome which is involved in the organisation of spindle fibres
What are flagella and cilia
They are extensions that provide from some cell types
Flagella are longer
There are more cilia
They contain 2 central microtubules surrounded by 9 pairs of microtubules
(9+2 arrangement)
What is the role of cilia
Stationary and mobile
Stationary cilia = present on surface of cells - important in sensory organs
Mobile cilia = best in rhythmic manner and causing a current making fluids move
What is the endoplasmic reticulum
Network of membranes enclosing flattened sacs called cisternae
Connected to outer membrane of nucleus
What is the smooth ER
Responsible for lipid and carb synthesis and storage
What is the rough ER
Has ribosomes bound to the surface
Responsible for synthesis and transport of proteins
What are ribosomes
Constructed of RNA molecules
They are the site of protein systhesis
What is the Golgi apparatus
Compact structure formed of cisternae
Doesn’t contain ribosomes
It’s modifies proteins and packages then into either secretory vesicles (leAve the cell) or lysosomes
What are the steps in protein production
- Synthesised on the ribosomes bound to the ER
- Pass into cisternae and are packaged into transport vesicles
- These vesicles move towards Golgi apparatus via transport function of cytoskeleton
- Vesicles dude with cis face of Golgi apparatus and proteins enter
Proteins are structurally modified by trans face in Golgi apparatus before leaving - Secretory vesicles carry the proteins to leave cells
