Chapter 2 Cells Flashcards
Define Organelles
Membrane bound compartments which provide distinct environments for different cellular reactions
Role and Structure of the cell surface membrane
Thin phospholipid, protein bilayer which is selectively permeable, controlling which substances enter and exit the cell. Can act a receptor for stimulus, cell signalling
Structure and Role of the nucleus
Contains genetic material inside double membrane (nuclear envelope to protect DNA), DNA acts a template for proteins, controlling activities of the cell. dNA forms a large complex with proteins called histones, called chromatin, which coils and condenses to form chromosomes. Contains the nucleolus where ribosomes are made, and nuclear pore in which RNA can leace
Structure and function of mitochondria
Double membrane, inner is highly folded called the Cristae, and matrix is the internal fluid, DNA inside
Site of the final stages of aerobic respiration
Structure and function of vesicles
Spherical fluid filled sacs which transport materials between organelles, and to outside/ inside the cell via the cell surface membrane. Moved by microtubules
Structure and function of lysosomes
Specialised forms of vesicles which contain hydrolytic enzymes necessary for destroying damaged organelles and foreign bodies, as well as apoptosis
Structure and function of the cytoskeleton- lot of detail and components of the cytoskeleton?
Microfilmants- contractile fibres made from the protein actin, responsible for cell movement and cytokinesis
Microtubules- made from polymerised globular Tubulin protiens, which form a scaffolding structure that determines cell shape, act as tracks for the movement of vesicles, act in spindle fibres for the separation of chromosomes
Intermediate fibres- give mechanical strength to the cell, maintain integrity
What is the structure and function of centrioles
Component of the cytoskeleton which is not found in plants and fungi
Two associated centrioles form the centrosome, which move to opposite end of the cell during cell division, producing microtubules during mitosis
Also position flagella and cilia
What are the 3 type of microtubules and role in cell division?
Kinetochore: extend outwards to chromosomes, attaching to the centromere. Cause the chromosomes lining up upon the midline of the cell, with the tug of war of chromosomes during metaphase position them, depolymerise so shorten during anaphase
Overlapping: Overlap, attaching to opposite centromeres, lengthen during anaphase
Astral: Out towards the cell membrane, stabilise it
Structure and function of flagella and cilia
Extension of the cells, containing two central microtubules, surrounded by wheel of them (9+2 arrangement)
Flagella enable cell motility, sensory
Cilia mobile=movement or stationary= sensory
Structure, type and function of endoplasmic reticulum
ER= network of membranes enclosing a fluid filled space
Smooth ER= Lipid and carbohydrate synthesis
Rough ER= Ribosomes bound. Produce proteins for external use
Structure and function of Ribosomes
Free floating or attached to RER
Two subunits, site of translation
Structure and function of the Golgi Apparatus :)
Fluid filled network of membranes, formed of cisternae
Modifying proteins such as adding carbohydrate chains, and packaging them into vesicles
Also produces lysosomes
What is the process of protein production (external)
(0. DNA nucleus transcription)
1. Proteins synthesised on ribosomes bound to RER
2. Pass through cisternae and packaged into transport vesicles
3. Vesicles move to the cis face of Golgi apparatus via the cytoskeleton transport function
4. Vesicles fuses with the cis face of the Golgi, structurally modified such as adding carbohydrate chains before leaving in a vesicle through the cisternae through the trans face
5. Secretory vesicles move to the cell surface membrane via the transport function of the cytoskeleton, fusing with membrane to release the proteins externally (exocytosis)
Structure and function of the cell wall
Cellulose cell walls to support the individual cell and the plant as a whole, defence mechanisms chemically, freely permeable
Structure and function of the vacuoles
Membrane lined sacs containing cell sap, maintain turgor
Membrane called toxoplasma, selectively permeable, transient and small in animals
Structure and function of chloroplasts
Double membrane structure, thylakoid membranes form thylakoid stacks, which stack together to form Granum. Granum are held to each other by thin sheets of membrane called lamellae. The internal fluid is called the stoma.
Site of Photosynthesis, with the grana containing chlorophyll needed for light depended part of the reaction
Difference in DNA between eukaryotic and prokaryotic
Structure fundamentally the same
Prokaryotes have one lone molecule of DNA, supercooled so more compact. Operons to group genes, which can be turned on and off. Circular. Controlled by proteins.
Eukaryotic have multiple chromosomes, linear. Controlled by histones
Difference of flagellum in prokaryotes
Thinner, no 9+2 arrangement
Energy from chemiosomsis
Attached to cell membrane by basal body
Difference apart from DNA of the two types of cells
Prokaryotes vs Eukaryotes
70s vs 80s ribosomes
Peptidoglycan vs chitin/cellulose
Binary fission vs asexual sexual reproduction
Non membrane bound organelles, both types
Which organelles are not membrane bound?
Some ribosomes
Cytoskeleton
Centrioles (not in plants)
Cilia/Flagellum
How do you separate small and large organelles?
Crush the cell so breaking them open
Centrifuge, heavier organelles sink, and including if bound to other organelles e.g ribosomes of RER
Do prokaryotes contain mitochondria, golgi apparatus, RER, vesicles?
No
What are the functions of the cytoskeleton?
Provide/maintain the shape of the cell
Movement of organelles e.g vesicles, or keeping organelles in their place
Provides mechanical strength
Cytokinesis
Formation of spindle fibres
Formation of cilia/flagella
How do vesicles moves?
Bind to the cytoskeleton
Movement via motor proteins
