Cell Structure And Function Flashcards
Organelles and function of different types of cells
What’s a prokaryotic cell
A cell with no nucleus e.g a bacteria
Robert Hooke 1665 in cell theory did what?
Robert Hooke was the first to describe cells
What is cell theory?
1) Cells are basic unit of life
2) everything living is composed of cells
3) cells can only develop from existing cells
What did Anton Van Leeuwenhoek 1674-1683 do in cell theory?
First person to observe bacteria and protoctista from pond water samples
What did Robert brown 1831 do in cell theory?
First to observe and describe a nucleus in a plant cell
What did Matthias Schleiden 1839 do in cell theory?
Matthias Schleiden- Suggested that all plant material is made from cells
What did Robert Remak 1852 do in cell theory?
Observed cell division
What did Louis Pasteur 1860 do in cell theory?
Disproved spontaneous cell generation
Cells come from existing cells
What is choroplast and it’s function?
Plant organelle
Where photosynthesis takes place
How do you calculate magnification?
Magnification (M) = size of image (l) ÷ actual size (A)
What are the limitations of light microscopes?
Lower magnification
Lower resolution
Need to be transparent material
What are some pros to light microscopes?
Cheap
Easy to use
What is Eukaryotic cells?
Cells that have a nucleus
What is a Golgi apparatus and it’s function?
A stack of membrane bound flattened sacs
Packages the proteins into vesicles to be transported
What is a nucleolus and function?
Spherical structure in the middle of the nucleus
It makes ribosomes and RNA
What is Rough endoplasmic reticulum and function?
Network of membrane bound flattened sacs called cisternae studded with ribosomes
Protein synthesis
What is Smooth endoplasmic reticulum and it’s function?
Network of membrane bound flattened sacs called cisternae NO RIBOSOMES
Responsible for synthesis and transport of lipids and carbohydrates
What is a vesicle and function?
Small spherical membrane sacs with fluid inside
Transport materials around the cell and outside of the cell
What is centrioles and it’s function?
They are small tubes of protein fibres
They form spindle fibres during cell division
What is tonoplast and function?
Partially permeable membrane of the vacuole
Allows small molecules to pass through
What is amyloplasts and it’s function?
A double membrane-bound sac containing starch granules
Responsible for the synthesis and storage of starch granules
What is plasmodesmata and it’s function?
Channels on the cell walls of plant cells
Enable transport and communication between individual plant cells
What are Pits and it’s function?
Pores in the cell walls of the xylem
Allow water to enter and leave xylem vessels
What is exocytosis?
The process of vesicles fusing with plasma membrane and secretary contents.
What is the function of animal cells?
Synthesise proteins for use inside cell and outside cell
Cell multiplication
What is a capsule and it’s function?
Slippery layer outside the cell wall
Protects the cell and prevents desiccation (prevents drying out)
What is a nucleoid and it’s function?
Irregularly shaped region (no nuclear membrane)
DNA and controls cellular activity
What is plasmid as it’s function?
Small loops of DNA
Carry genes that may benefit the survival of the organism
What do bacteria cells do?
They produce and secrete toxins
What do Gram-negative bacteria have?
A thinner cell wall and 2 lipid membranes
What colour are gram-positive
Purple
What colour is Gram-negative bacteria?
Pink
Why is Gram-negative pink?
Thinner cell walls and lipid membranes allows ethanol to wash off the crystal violet purple stain
But keep the pink safranin stain
What type of bacteria is spherical shape?
Cocci
What type of bacteria is rod shape?
Bacilli
What type of bacteria is spiral shape?
Spirilla
What type of bacteria is comma shaped?
Vibrios
What type of bacteria is corkscrew shaped?
Spirochaetes
What are main features of fungal cells
Nuclei with chromosomes
No chlorophyll
Absorb food they are osmotrophic
Reproduce by means of spores
What is lysosome and it’s function?
Contains digestive enzymes to break down worn out cell parts or bacteria
What is centrosome for?
Cell division
What are erythrocytes?
Red blood cells
What are leucocytes?
White blood cells
What are thromcytes?
Platelets
What does semi-permeable mean?
Controls what enters the cell
What does permeable mean?
Everything can enter the cell
What does inpermeable mean?
Nothing can enter the cell
What does ATP mean?
Adenosine triphosphate
What is the function of centriole?
Produces spindle fibres for mitosis (cell division)
What is the function of peroxisome?
Fulfils essential metabolic functions in lipid metabolism, both catabolic and anabolic
What did Jan Purkyne do in cell theory 1839?
Jan Purkyne- animal tissue is made from cells and have similar structure to plant tissue
What did Theodor Schwann 1839 do in cell theory?
Theodor Schwann- proposed all living things are made from cells
Light microscope advantages and disadvantages?
Advantages
Cheap
Easy to use
Disadvantages
Poor magnification
Poor resolution
Electron microscope advantages and disadvantages?
Advantages
Good magnification
Good resolution
Disadvantages
Expensive
Need training to use
What is a nucleoid?
Single circular length of DNA folded up in bacteria
What is a slime capsule?
Polysaccharide layer outside the cell wall
What is the functions/roles of the polysaccharide layer?
Prevents the cell drying out
Helps protect from white blood cells
Helps stick to surfaces
What is the functions/roles of the cell wall in bacteria?
Made of sugar and amino acids called peptidoglycan
Support and protection
Keeps its shape
How do you calculate image size?
Actual size X magnification
How do you calculate actual size?
Image size/magnification
What types of ribosomes are in bacteria?
70s ribosomes
How can you remember what gram-negative colour is
Gram negative is pink they both have the letter n in them
