Basic Principles - Organelles Anatomy Flashcards
Lecture 1
Explain the structure of the nucleus and its function.
Nucleus is enclosed within nuclear envelope which houses chromatin, nucleoplasm and nucleolus.
Nucleolus synthesises ribosomes.
Nucleus houses DNA that serves as genetic material for protein synthesis.
Nuclear pores control what enters and leaves the nucleus.
Explain the structure and function of the cell membrane.
Phospholipid bilayer with proteins scattered throughout. Hydrophilic polar heads and hydrophobic non-polar tails.
Selectively permeable, establishes electrochemical gradients and contains receptors for communication.
Explain the structure and function of rough endoplasmic reticulum.
Ribosomes attached to cisternae.
Interior of RER is a compartment separate from the cytoplasm
Synthesise of secretory and membrane proteins, quality control and degradation process.
Ribosomes attached to surface are responsible for translating mRNA into polypeptide chains, which are then translocated into the lumen of the RER
Explain the structure and function of smooth endoplasmic reticulum.
No ribosomes.
Function is to synthesise lipids.
Forms vesicles and peroxisomes.
Explain the structure and function of lysosomes.
Formed from Golgi apparatus.
Contain hydrolytic enzymes which digest microbes.
Explain the structure and function of Golgi apparatus
Modifies and secretes materials from endoplasmic reticulum and forms secretory vesicles and lysosomes.
Cis is receiving face and trans is shipping face.
cisternae present
Explain the structure and function of mitochondria.
Contains mitochondrial matrix.
Cristae increase SA via foldings of inner membrane.
Function is to produce ATP, also cell death, maintenance.
Mitochondrial DNA is inherited strictly from mother to child.
Explain peroxisomes
Small, spherical shaped membrane bound organelles that provide contained environment for detoxification of harmful substances taken into a cell.
Contain oxidative enzymes within the matrix
Can proliferate and divide in response to cellular needs and environmental conditions
Surrounded by a single lipid bilayer membrane
Explain the term proteasome
Large barrel shaped protein complexes in cytosol and nucleus
Degrade and digest damaged proteins and ensure quality of exported proteins
Explain the term cytoskeleton
Composed of microtubules, microfilaments and intermediate filaments
Structural function - provides structural support, determines cell shape and stabilises junctions between cells
Movement function - assists with cytosol streaming and cell motility, moves organelles and moves chromosomes during cell division
Explain the term centrioles
Short lengths of microtubules, located in centrosome.
Single centriole found in basal end of cilia and flagella
Functions;
* organisation of microtubules - organising centers for the assembly of the mitotic spindle apparatus during cell division
* formation of basal bodies - structures that anchor and organise the microtubules of cilia and flagella
Explain the term microvilli
Numerous thin membrane folds projecting from apical surface supported by actin microfilaments.
Increase surface area for absorption.
Actin microfilaments anchor to terminal web (intermediate filaments) stiffening microvilli and keeping actin bundles at a right angle to the cell.
Explain the term cilia
Short hair-like appendages with microtubules at centre.
Arranged in a ring of 9 special double microtubules with a pair of single microtubules at the centre.
Move substances over cell surface.
Explain the term flagella
Function is locomotion.
Found on sperm cells
Long singular membrane extensions supported by microtubules
Contain motor protein dynein
