B1.1 - Cell Structures Flashcards
What are eukaryotes?
Organisms consisting of cells in which the genetic material is contained within the nucleus in the form of DNA
What are prokaryotes?
Prokaryotes are unicellular organisms with no nucleus or membrane-bound organelles
Genetic material is mainly within the cytoplasm
What are pathogens?
Microorganisms that cause diseases
What are the pili and their function?
Tiny hairlike structures
Helps attach to surfaces and transfer genetic material
What is a slime capsule and its function?
Layer outside the cell wall
Protects from drying out and poisons
Also to stick to smooth surfaces.
What are plasmids and their function?
Circular pieces of DNA used to store extra genes
Not needed daily but during times of survival for antibiotic resistance
What are flagella and their function?
Tail-like structures
Allows the cell to move through lipids
What are ribosomes and their function?
Ribosomes are tiny granules on the membranes in the cytoplasm where proteins are made
What do each of the letters in MRS GREN represent?
M - Movement
R - Respiration
S - Sensitivity
G - Growth
R - Reproduction
E - Excretion
N - Nutrition
They represent all the 7 life processes that all living things go through
How big are eukaryotic cells normally?
10 - 100 micrometres
How big are prokaryotic cells normally?
0.1 - 5 micrometres
What is the nucleus and its function?
Controls the cell and contains genetic material, determining its appearance and function
What is the cytoplasm and its function?
Jelly-like substance where chemical reactions take place
What is the mitochondria and its function?
Where respiration takes place
Releases energy for the cell
What is the cell membrane and its function
Delicate surface membrane made of two layers of phospholipid
Holds the cell together
Controls what goes in and out of the cell
What is the cell wall and its function?
Provides support for structure by surrounding the cell
Made out of cellulose
What is the vacuole and its function?
Contains cell sap
Controls water levels in the cell
Keeps cell shape firm
What is the chloroplast and its function?
Harnesses energy from the sun for photosynthesis
What is the main difference between eukaryotes and prokaryotes?
Eukaryotic cells have nuclei
Prokaryotic cells don‘t
What are the two types of electron microscopes?
TEM - Transmission electron microscope
SEM - Scanning electron microscope
What are SEMs used for and how have they advanced science?
SEMs has a large depth of field so can be used to examine the surface structure of specimens.
They produce a 3-D image of a surface by bouncing a beam of electrons off of a specimen.
What are TEMs used for and how have they advanced science?
TEMs are used to examine an extremely thin slice or section of cells or tissues
TEMs have revealed subcellular structures in cells not visible with a light microscope such as mitochondria and chloroplasts
What part of a cell does methylene blue stain?
Animal cell nuclei
Wha part of a cell does iodine stain?
Plant cell nuclei
What part of a cell does crystal violet stain?
Bacteria cell walls
Formulae for magnification (name both)
Optical lens magnification x objective lens magnification
Size of image/ actual size of the object
How to find the actual size of an object on a microscope?
Size of image/ magnification
Who built the first compound microscope ?
Robert Hooke
