2.4-2.6 ultrastructure of the cell Flashcards
(19 cards)
what are the 15 components of an animal cell?
nucleus, smooth endoplasmic reticulum, rough endoplasmic reticulum, ribosomes, golgi apparatus, lysosomes, mitochondria, chloroplasts, centriole, flagella, cilia, cytoskeleton, vesicles, plasma membrane.
describe the nucleus
-nuclear envelope- consists of a double membrane to protect the nucleus from damage in the cytoplasm
-nucleolus- where ribosome synthesis takes place (RNA synthesis)
-chromatin- contains the cells DNA
-nuclear pores- allows substances such as mRNA in and out the nucleus
describe the smooth endoplasmic reticulum (SER)
-made up of cisternae (membrane bound sacs that form sheets of interconnected tubules)
-involved in lipid and carbohydrate synthesis and storage
describe the rough endoplasmic reticulum (RER)
- made up of cisternae ( membrane bound sacs that form sheets of interconnected tubules)
- covered in ribosomes for protein synthesis
-transorts proteins
describe ribosomes
- they are free floating or bound to the RER
- they are the site of protein synthesis
- made up of RNA in the nucleus
describe mitochondria
- has a double membrane and the inner membrane is made up of cristal which is highly folded to increase surface area
-has mitochondria DNA (m+ DNA) to allow mitochondria to produce enzymes and reproduce itself
-contains matrix which is the enzyme for reparation
describe a lysosome
-contains powerful hydrolytic digestive enzymes ( lysosymes ) to break down damaged or dead components of the cell
-involved in programmed cell death
-engulf invading cells and damages components of the cell
- it is a specialised vesicle
describe chloroplasts
-contains thylakoids which are linked my lamellae to form grana
-contains a fluid called storm which contains starch, lipids, DNA and RNA
-site of photosynthesis
-has a double membrane
describe the plasma membrane
-it is made up of a phospholipid bilayer which is semi-permeable
-has receptor molecules which respond to hormones
-controls what comes in and out the cell
describe flagella
- it has a 9+2 arrangement of microtubules
-it allows mobility of the cell - it can detect chemical changes around the cell
describe cilia
- it has a 9+2 arrangement of microtubules
- involved in locomotion and has a sensory function
describe the centriole
-it is a component of the cytoskeleton that has 9x triplet microtubules
-it forms the spindle fibres during cell division
describe the cytoskeleton
-microtubules- transport of substances, made up of a globular protein called tubulin
-intermediate fibres- made up of a protein that forms contractile fibres called actin, involved in movement and contraction of the cell
-microfillaments- maintains strength and integrity of the cell
describe vesicles
membranous sacs involved in store in transport
describe the golgi apparatus
-transports, processes and modifies packages into vesicles
-site of lysosomes and lipid synthesis
-made up of cisternae ( membrane bound sacs that form sheets of interconnected tubules
what extra components are found only in plant cells
b cellulose cell wall and a vacuole
describe a vacuole
-membrane ( tonoplast ) bound
-contains cell sap to maintain cell shape by maintaining turgor pressure
- store for sugars and amino acids
describe the be cellulose cell wall
- made up of cellulose which is made up of beta glucose
-provides strength and support to the cell - middle lamella marks boundaries and cements adjacent cells
identify some differences between prokaryotic cells and eukaryotic cells
differences:
- E has membrane bound organelle whereas P doesn”t
-E’s DNA is contained within a nucleus and is linear where as P’s DNA isn’t and is circular
-P evolved before E
-P has smaller ribosomes 70s compared to E with 80s
-P cell walls are made up of peptidoglycan instead of cellulose or chitin
-P flagella doesn’t have a 9+2 arrangement and gets its energy from chemiomosis not ATP
-P is reproduces via binary fission and E is meiosis or mitosis
