Module 2-Cells Flashcards
Eukaryotic cell basic features
~Make up complex eukaryotic organisms
~Larger than prokaryotes
~Cells arise by mitosis or meiosis
~Cell surface membrane is made up of a phospholipid bilayer
Prokaryotic cell features (do not talk about subcellular structures)
~Make up single celled prokaryotic organisms
~Cells arise from other cells by binary fission
~Do not have membrane bound organelles
What are the sub-cellular structures in animal cells?
Mitochondria, ribosomes, ER, golgi, lysosomes, nucleus, cell membrane, centrioles
What are the sub-cellular structures in plant cells?
Mitochondria, ribosomes, ER, golgi, nucleus, cell membrane, vacuole, chloroplasts, cell wall made of cellulose
What is the nucleus?
Contains the cells DNA and is surrounded by a nuclear envelope
What is the nuclear envelope?
Double membrane structure that has a number of pores. Both membranes are phospholipid bilayers. The pores control the passage of ions, molecules and RNA between the nucleoplasm and cytoplasm.
What is the nucleolus?
Made of proteins, RNA and DNA. Ribosomal RNA is joined together with associated proteins in the nucleolus to assemble the ribosomal subunits. Secondary roles include immobilising proteins and forming signal recognition particles.
What is the mitochondria?
The mitochondria makes ATP via aerobic respiration.
Describe the structure of the mitochondria
Oval shaped, double mebraned organelle that have their own ribosomes and DNA. Each membrane is a phospholipid membrane embedded with proteins. The inner layer of the membrane has folds called cristae, the area surrounded by the folds is called the mitochondrial matrix which contains membranes used for respiration.
What is the golgi apparatus?
series of flattened membranous sacs that release golgi vesicles. They also transport, package and modify proteins and lipids into vesicles for delivery to targeted destinations.
What is the structure golgi vesicles?
Membrane bound, fluid filled vesicles located in the cytoplasm. They are small, round and are seen in a high density near the edges of the golgi sacs.
What are lysosomes and lysozymes?
Lysosomes are a type of golgi vesicles which store and transport modified proteins and lipids from the golgi apparatus to target cells. Lysozymes are enzymes in the lysosomes which aid the breakdown of proteins, polysaccharides, lipids, nucleic acids and old organelles.
What are the ribosomes?
Can be free floating in the cytoplasm or attached to the cytoplasmic side of the ER. They are very small and made of protein sub units. They aren’t covered by a membrane and are in charge of protein synthesis.
What is the ER in general?
a series of interconnected membranous sacs and tubules responsible for modifying proteins and synthesising lipids. Membrane is a phospholipid bilayer embedded with proteins.
What is the RER?
RER has ribosomes on its surfaces and is responsible for processing and folding proteins.
What is the SER?
SER has no ribosomes on its surface and is responsible for making and processing lipids.
What is the plasma membrane?
The fluid mosaic model says that it is made up of a variety of components that are continuously moving around. they are partially permeable and the attachment point for some extracellular and intracellular structures.
What is the cell wall?
Rigid covering that protects the cell. Plant and agal cell walls are made of cellulose, fungal cell walls are made of chitin. Provide structural support and provides shape for the cell.
What are centrioles?
have a cylindrical shape and are made up of parallel micro tubules that surround a central cavity. Mostly found in pairs that are arranged at right angles to each other. Are a key component of centrosomes which are crucial for organising micro tubules in the cell and help organise the mitotic spindle during cell division.
What are flagella?
hair like structures
eukaryotic flagella have a 9+2 arrangement, bacterial flagella are helical and are mainly made up of protein flagellin.
are used by some organisms for locomotion
eukaryotic flagella generate propulsion using a whipping motion whereas bacterial flagella move in a propeller way.
What are cilia?
have a central core called axoneme. primary cilia have a 9+0 arrangement whereas motile cilia have a 9+2 arrangement. Help to move substances internally by synchronising their beating.
What are the jobs of the cytoskeleton?
-maintains cell shape
-secures some organelles in specific positions
-allows cytoplasm and vesicles to move within the cell
-enables cells with multicellular organisms to move
What are the 3 types of protein fibre within the cytoskeleton?
-microfilaments
-intermediate filaments
-microtubules
What is the role and structure of the microfilaments?
-thicken the cortex within the inner edge of a cell and resist tension
-made of 2 intertwined strand of globular proteins (called actin) which works with a motor protein (called myosin) to help cellular events requiring motion
-can disassemble and reform quickly allowing the cell to change its shape and move. White blood cells make use of this ability as they can move to the site of infection and phagocytose the pathogen.
