Cell structure and microscopes Flashcards
What is the structure and function of Lysosomes?
They are vesicles that contain hydraulic enzymes( lysozymes) to break bonds and break down molecules.
What is the structure and function of Centrioles?
They are paired barrel shaped organelles located in the cytoplasm of animal cells near the nuclear envelope. They organise microtubules that serve as the cells skeletal system.
What is the structure and function of the cytoskeleton?
Its made up of microtubules, actin filaments and intermediate filaments/ a network of protein fibres. They form cell shape, allow cell to move and allows organelles to move within the cell.
What is the structure and function of cell surface membrane?
Plasma membrane - partially permeable. It separates the interior of the cell from the surrounding environment
What is the structure and function of ribosomes?
They are very small (20nm), spherical structures which are free in the cytoplasm. They make/assemble proteins for protein synthesis and make/assemble protiens which are going to be used inside the cell.
What is the structure and function of the rough endoplasmic reticulum?
It continues with the outer nuclear membrane. It is folds of membrane that have ribosomes on their outer surface. It produces proteins from ribosomes on its surface and sends them to another organelle to be packaged and sent out of the cell.
What is the structure and function of the Golgi apparatus?
It is fused cisternae, flattened membrane. It modifies (adds molecules to proteins), packages and labels substances like proteins before sending them in Golgi vesicles to different parts of the cell.
What is the structure and function of the smooth endoplasmic reticulum?
Its a long network of folded tube like structures. It makes, moves and packages lipids and carbohydrates.
What is the structure and function of the nucleus?
It contains DNA which is linear and is tightly wound around histone proteins to form thread like structures called chromosomes.
What is the structure and function of the nucleolus?
It is the largest structure in the nucleus. It makes ribosomal RNA to form functioning ribosomes.
What is the structure and function of the nuclear envelope?
The nucleus is surrounded by a double membrane called the nuclear envelope which contains nuclear pores. It allows some molecules to move out of the nucleus NOT DNA.
What is the structure and function of mitochondria?
Double membrane - cristae, matrix, outer and inner membrane, inter membrane space. Its the site of aerobic respiration - produces ATP
What is the structure and function of the cytoplasm?
Cytosol - gel like substance.
Where all the chemical reactions in the cell take place and where all the membrane bound organelles are held.
It separates the organelles from the external environment.
What is the difference between a prokaryotic and a eukaryotic cells?
Eukaryotic cell: contains a nucleus and membrane bound organelles.
Prokaryotic cell: No membrane bound organelles, no nucleus so genetic material free floating.
What is the cell wall in a prokaryotic cell made from?
Peptidoglycan
What is the structure and function of a capsule in a prokaryotic cell?
Around the outside of cell, helps prokaryotic cell cling to each other and various surfaces, its a defence against host cells and prevents cell from drying out.
What is the structure and function of pili in a prokaryotic cell?
They are short hair like structures on cell surface which increase surface area, they are involved in adherence to surfaces - facilitates infection, they have a role in movement.
What is the structure and function of a flagellum in a prokaryotic cell?
Some prokaryotic cells have them, they help an organism in movement, they are sensory organs so they detect temperature and pH and they get energy from chemiosmosis which is movement of H+ across a biological membrane - generates ATP
What is the structure and function of free chromosomal DNA in a prokaryotic cell?
Nucleoid region
allows direct connection to translation and transcription
contains genetic material
What is the structure and function of a ribosome in a prokaryotic cell?
Smaller than 70s
Different type of ribosome made of proteins - tRNA
Explain the cell surface membrane of a plant cell
made out of cellulose - beta glucose chains hold together by hydrogen bonds. fully permeable to and contents of the cell push against it allowing it to support the cell and those around it. If there is not enough water present the cell wall holds onto the water and supports - stops cell from collapsing, if there is too much water present the cell wall prevents lysis
(cell bursting)
Explain the structure and function of chloroplasts
They are found in the areas above ground in plants. They have a double membrane, fluid in the centre in the stomata. Internal membranes are made of flattened sacs called thylakoids and stacked to make grana. The grana contain photosynthetic pigments like chlorophyll
Explain the structure and function of the permanent vacuole
Membrane bound sac containing cell sap. The membrane is often called tonoplast. It stores cell sap and may also store nutrients and proteins. Keeps cell turgid (swollen and hard). Some play a similar role to lysosomes - digest