Unit 2 Cells Structure + Function Flashcards
What is the nucleus surrounded by and what is it called?
Nucleus is surrounded by a double membrane called a nuclear envelope
What does the nuclear envelope have and what can that do?
The nuclear envelope has pores which allows molecules to enter and leave the nucleus.
What 2 other things does the nucleus contain?
1) Nucleolus
2) Chromatin
What process do the Nucleolus and Chromatin help with?
Ribosome production
Describe what the
Rough endoplasmic reticulum is like?
It is a series of flattened sacs enclosed by a membrane with ribosomes on the surface.
What does the rough endoplasmic reticulum do?
It folds and processes proteins made on the ribosomes.
Describe what the Smooth endoplasmic reticulum is like?
It is a system of membrane bound sacs.
What does the Smooth endoplasmic reticulum do?
It produces and processes lipids.
Describe what the golgi apparatus is like?
A series of fluid filled, flattened & curved sacs with vesicles along the edges.
What does the golgi apparatus do?
It processes and package lipids and proteins.
What is an extra job the golgi apparatus can do?
It produces lysosomes.
(*) What is a lysosome?
An organelle in the cytoplasm of eukaryotic cells that contains degradative enzymes.
Describe what a mitochondrion is like?
It is oval-shaped bound by a double membrane called the envelope.
What happens to the inner membrane of the mitochondria?
It is folded to form projections called cristae.
What are the purpose of cristae?
Cristae have matrix on the inside which contain all the enzymes needed for respiration.
What are centrioles?
They are hollow cylinders containing a ring of microtubules arranged at right angles to each other.
What process are centrioles important for?
Cell Division
Which organelle is the site of protein production?
Ribosomes
3 things the cytoskeleton of the cell does?
1) Mechanical strength
2) Aiding the transport within cells
3) Enabling cell movement
Where are proteins produced?
Proteins are produced on ribosomes.
What is the 1st step of protein transportation
around the cell?
1) The proteins are produced on the ribosomes.
What is the 2nd step of protein transportation around the cell?
2) The proteins are produced on the surface of the RER and are folded and processed in the RER.
What is the 3rd step of the protein transportation around the cell?
The proteins are then modified in the Golgi apparatus.
What is the 4th step of the protein transportation around the cell?
The proteins are further processed within the golgi apparatus
What is the 5th step of the protein transportation around the cell?
The proteins are transported to the cell surface membrane in vesicles.
What is the 6th step of the protein transportation around the cell?
These vesicles are then further fused with the cell surface membranes to release the proteins.
How do extremely large molecules pass through the nucleus?
They pass through the nuclear pores.
How are the RER and the Outer nuclear membrane linked?
The Outer nuclear membrane is continuous with the connection of the RER.
Describe the Nucleoplasm?
The nucleoplasm is an aqueous, jelly-like substance within the nucleus.
What does rRNA stand for?
Ribosomal RNA
What does the Nucleolus create?
The Nucleolus creates rRNA and ribosomes
How does the nucleus control the cell?
The nucleus contains the genetic material which codes and has the instructions for proteins via protein synthesis.
What does the DNA in the nucleus produce during transcription?
mRNA
What does mRNA stand for?
Messenger RNA
What does the matrix within mitochondria mean?
The matrix within mitochondria means the jelly-like, aqueous substance.
The mitochondria is the site of which type of respiration?
Aerobic respiration
How do cristae help the mitochondria?
Cristae increase the Surface Area for attachment of respiratory proteins.
What 2 things are ribosomes made form?
rRNA and proteins.
What are the 2 subunits within ribosomes in eukaryotic cells?
60S subunit and 40S subunits which make 80S
What are the 2 subunits within ribosomes in prokaryotic cells?
50S subunits and 30S subunits which makes 70S
What happens between mRNA and tRNA during translation?
mRNA and tRNA polymerise amino acids to form polypeptide chains.
What is the Golgi apparatus made made up of?
Stacks of cisternae with small structures called vesicles.
What is the name of the process that allows vesicles to deliver substances out and within the cell?
Exocytosis
What substance do lysosymes hydrolyse?
Lysosymes hydrolyse pathogens.
What is autolysis?
Lysosymes hydrolysing old cells, organelles.
What type of membrane does the SER consist of?
SER has a single membrane
What type of membrane does the RER consist of?
RER has a single membrane
What type of membrane does the eukaryotic organisms have?
Eukaryotic organisms have a double membrane
What is the cell membrane of the cell consist of mostly ?
Phospholipids and cholesterol
How does cholesterol help the cell membrane?
Cholesterol helps to provide structural support as well as act as a glue between phospholipid molecules.
What can excess cholesterol do to the cell membrane?
Excess Cholesterol can increase the rigidity of the cell membrane leading to increased pressure within the cell.
What can minimal cholesterol do to the cell membrane?
Minimal cholesterol can loosen the structural support between the phospholipid molecules and the cell membrane so it can degrade
What structure does the phospholipid heads along the double membrane form?
The phospholipid bilayer
What is the name for external proteins on the cell membrane?
Integral proteins
What is the name for internal proteins within the cell membrane?
Peripheral proteins
What is the importance of substance being able to travel through the cell membrane?
It allows the maintenance of a concentration gradient.
Name 3 other molecules that involved within the cell membrane?
Glycolipids, glycoproteins and carbohydrates
What type of membrane do chloroplasts have?
They have a double membrane called the envelope.
What is the stroma within the chloroplasts?
The Stroma is the aqueous, jelly-like substance filled within the chloroplasts.
What are Thylakoids?
Thylakoids contain chlorophyll in the shape of stacks called grana
How specifically are the grana within the thylakoids connected to the chloroplasts?
The grana within the thylakoids are connected to the chloroplasts by integral lamellae
What is the cell wall of a plant made up of?
Plant cell wall is made up of a polysaccharide lattice of microfibrils which in turn make up cellulose.
What is the cell wall of fungi made up of?
Fungal cell walls are made up of a polysaccharide latice of microfibrils made up of chitin.
What is the middle lamella within the mitochondrion help with?
Adhesion with adjacent cells
What is the main function of the cell wall?
Helps aid mechanical strength to the cell
What can the cell wall prevent? (2 things)
Cell bursting under osmotic pressure and prevents plant from collapsing due to its own weight
What is the feature that the cell wall contains that allows substances to exit and enter?
It has a free permeability
What process and how does free permeability help with the movement of substances within the cell wall?
Transpiration in plants where water and other substances can easily pass through the cell wall
What is the vacuole?
A large fluid filled sac that stores mineral ions, starch, glucose, proteins, lipids and amino acids
What is one use of the vacuole?
Temporary food storage
What is the main function of the vacuole?
Supports the cell by pushing against the cell wall which allows a stable osmotic pressure to occur.
When there is a high osmotic pressure in the cell of a plant what is it called?
Turgidity
What does the structure of a virus consist of?
Attachment proteins
Lipid Envelope
Nucleic Acids
Protein coat
What is the name of the protein coat in a virus called?
A Capsid
What are the 2 types of Nucleic Acids?
DNA or RNA
What are the Nucleic Acids in Viruses used for?
Nucleic Acids are used for transfer and replicating their genetic material into other hosts
What type of Virus is HIV?
It is a retrovirus which replicates its DNA by remaking it in the host cell
What are attachment proteins?
Attachment proteins are on the surface of Viruses to help bind to host cells so they can inject their nucleic acids into them
What does the immune system detect the Attachment proteins as?
The immune system releases white blood cells to detect them as foreign particles and antigens.
(E*) How does the Virus transfer its RNA into our DNA?
Our DNA is captured by the Virus
The Viral RNA is duplicated and made into a double strand of DNA.
This fake DNA is injected back into the cells
What are organelles like in bacterium’s?
The organelles are found as non-membrane bound organelles
What is the organelle that enables the bacterium to move through different mediums?
Flagella or Flagellum
What does the plasmid do?
It provides genetic variation between other bacteriums in the bacteria colony
How are the genetic material within a bacterium contained?
They are free floating single loop DNA within the cytoplasm
What does a slime capsule allow the bacterium to do?
The slime capsule allows the bacterium to attach to its external environment
What are pili in terms of the bacterium?
Pili are use to exchange genetic material during a type of reproduction called conjugation
What are fimbriae in terms of bacteria?
Fimbriae are used to allow the bacteria to attach to the host cell
Give an example of one trait that is passed via plasmid transfer through a bacteria colony?
The plasmid transfer on antibiotic resistance can be passed through a bacteria colony
What is the process by which bacteria replicate?
Binary Fission
What organelles are involved in the process of binary fission?
The single loop of DNA and the plasmids
What is a tissue?
Cells specialised to perform specific functions with similar structures
