2.1 cell structures Flashcards
chromatin
material from which chromosomes are made
nucleolus
sites of ribosome production
RER - ROUGH ENDOPLASMIC RETICULUM
covered in ribosomes processes proteins made by ribosomes
SER - SMOOTH ENDOPLASMIC RETICULUM
involved in production, processing and storage of carbs, lipids and steriods
GOLGI APPARATUS
flattened sacs of protein modifies proteibs ad packages them into vessicles or lysosomes
RIBOSOMES
each ribosome is a complex of ribosomal RNA (rRNA) and proteins
LYSOSOME
cotain hydrolytic enzymes break down waste materials - worn outorganelles
HYDROLTIC ENZYMES
ENZYMES THAT BREAK BIOLOGICAL MOLECULES DOWN
CHLOROPLAST
double membrane
membrabe bound compartments thylakoids– contain chlorophyll -
and stack to form structures called grana
grana joined by lamellae
light dependant stage - thylakoids
light independant - stroma
PLASMA MEMBRANE
partially permeable formed from layer of phospholipid
CENTRIOLE
hollow fibres made of microtubules organises spindle fibres during cell division
CELL WALL
freely permeable structural support plants - cellulose bacteria- peptidoglycan fungi - chitin
flagella
longer microtubules contract to provide cell movement
cilia
hair like allows movement of substances over cell surface
CYTOSKELETON
provide mechanical strength to cells
aiding transport within cells
enables cell movement
OPTICAL MICROSCOPES
Relatively cheap easy to use Portable Use visible light Ribosomes cannot be examined
LASER Scanning microscope
Uses laser light to scan an object point by point and assemble the pixel into one image using a computer high resolution High Contrast HAVE DEPTHx SELECTIVITY USED IN MEDICAL PROFESSION
Electron microscope
Uses beam of fast travelling electrons Electrons fired from cathode and focused by magnets onto a screen Much greater resolution Highly magnified Expensive Large Skill and training required Have to be dead Metallic salts have to be used and are potentially hazardous
Total magnification
power Of objective lens X power of eyepiece lens
Why do we stain samples before viewing under a light microscope
Contrast and to identify certain sub cellular structures better
Maximum magnification for a scanning electron microscope
X 200,000
NUCLEUS
seperated from the cytoplasm by a double membrane which has many pores. Contains chromatin
nuclear pores
allow mrna and ribosomes to travel out of the nucleus.
