Topic 2 - Cell Structure Flashcards
What is a eukaryotic cell?
Holly organised structures that contain a nucleus and membrane bound organelles allowing them to perform specialised functions.
What is the nucleus structure?
Surrounded by a double membrane with nuclear pores, allowing molecules to move in and out.
Chromatin: DNA and associated proteins.
Nucleolus: produces ribosomes
Nucleoplasm: jellylike substance that forms the bulk of the nucleus
What is the structure of the rough endoplasmic reticulum?
A network of flattened sacs enclosed by a membrane. Surface is studied with ribosomes.
What is the function of the rough endoplasmic reticulum?
Folds and processes, proteins synthesised by the ribosomes
What is the structure of the smooth endoplasmic reticulum?
A network of membrane bound sacs without ribosomes.
What is the function of the smooth endoplasmic reticulum?
Synthesis and processes, lipids.
What is the structure of the Golgi apparatus?
A stack of fluid filled flattened sacs with vesicles at the edges.
What is the function of the Golgi apparatus?
- Modifies packages and transport proteins and lipids.
- Produces lysosomes.
What is the structure of ribosomes?
Made of two sub units and found either free in the cytoplasm or attached to the rough endoplasmic reticulum.
What is the function of the ribosomes?
Site of protein synthesis.
What is the structure of the mitochondria?
Oval shaped surrounded by a double membrane.
The inner membrane is folded into cristae which increases the surface area for respiration.
The internal space called the matrix contains enzymes needed for aerobic respiration to produce ATP .
What is the structure of lysosomes?
Small vesicles bound by a single membrane containing digestive enzymes.
What is the function of lysosomes?
Breakdown waste materials, old organelles and pathogens.
What is the structure of a centriole?
Hollow cylinders made of microtubules arranged at right angles to each other.
What is the function of centrioles?
Organise the spindle fibres during cell division.
What is cell specialisation?
The process by which cells develop specific structures and functions to perform particular roles within an organism.
Compare the shape size and organelle adaptions of muscle cells and red blood cells.
Muscle cells contain many mitochondria to provide energy for contraction while red blood cells are specialised for carrying oxygen due to their lack of nucleus and presents of haemoglobin.
What is cell differentiation?
The process to which unspecialised cells become specialised.
How does differentiation work in terms of genes?
Certain genes are activated or deactivated, allowing the cell to produce specific proteins required for its function.
What is the function of a nerve cell and how is a nerve cell adapted to its function?
Function: transmit electrical signals throughout the body.
Adaptions: it has a long axon to carry impulses it has a myelin sheath which insulates the axon speeding up electrical transmission and finally many dendrites to connect with other neurons.
What is the function of an epithelial cell and how is it adapted to its function?
Function: forms of protective layers or aids absorption
Adaptions: cells in the intestine have microvilli which increase surface area for nutrient absorption and some have cilia to remove mucus in the respiratory tract.
What is the function of a sperm cell and how is it adapted to its function?
Function: fertilise an egg.
Adaptions: flagellum mobility, many mitochondria to provide energy for swimming and an acrosome contains enzymes to penetrate the cell membrane.
What is the relationship between cells tissues organs and organ systems?
Specialised cells group together to form tissues, tissues combined to form organs and organs work together to form organs systems.
What is a cell?
The basic unit of life and is specialised to perform specific functions.
What is a tissue and give an example?
Groups of similar cells working together to perform a particular function.
Example: muscle tissue contract for movement while epithelial tissue line surfaces.
What is an organ and give an example?
Structures made of several tissues that work together to perform complex functions.
Example: the heart pumps blood using muscle, tissue, nerve tissue and connective tissue.
Give an example and explain what is an organ system?
Groups of organs that work together to carry out vital processes.
Example: the digestive system includes organs like the stomach and intestines to breakdown and absorb food.
What is a prokaryotic cell?
Simple cells that lack a true nucleus and membrane bound organelles. They are smaller than nucleic cells and have structural adaptions for their specific roles such as a bacteria cell.
What are the seven features of a prokaryotic cell?
Cell wall
Capsule
Plasmid
Flagellum
Pili
Ribosomes
Mesosomes
What is the function of the cell wall in a prokaryotic cell?
Provides structural support and protection against osmotic pressure.
What is the function of the capsule in a prokaryotic cell?
A protective slimy layer outside the cell wall helps to retain moisture and adhere to surfaces. It offers protection against the immune response of host organisms.
What is the function of a plasmid or circular DNA in a prokaryotic cell?
Contains genes for survival traits such as antibiotic resistance.
What is the pili in a prokaryotic cell?
Thin hair like projections on the surface of the cell and I used to attach to other bacteria cells or surfaces.
What is the function of a mesosome?
Contains enzymes required for aerobic respiration and increases surface area for metabolic reactions.
What is the constitution of a virus?
Nonliving structures.
Made of: nucleic acid as genetic material a protective coat called the acid and some viruses are surrounded by a lipid layer known as the envelope.
Compare prokaryotic and eukaryotic cells
Small - larger
No true nucleus - nucleus enclosed by envelope
Single/circular DNA - linear DNA associated with histones
No membrane bound organelles - membrane bound organelles
70s ribosomes - 80s ribosomes
Binary fission - mitosis and meiosis
Contains plasma - doesn’t contain plasma
How do viruses replicate?
They can only replicate in a wholesale they inject them material into the host cell hijacking the hosts machinery to replicate and assembled new virus.
What are the five differences between viruses and bacteria?
Non-cellular particles - prokaryotic cells
Can be DNA or RNA single or double stranded - circular strand of DNA
Replicate inside a host cell - divide by binary fission
Smaller - larger
Require a host cell to live - can survive and multiply without a host cell.
