Cell structure Flashcards
(43 cards)
State 4 features found in both animal and plant cells
Plasma membrane
Nucleus
Cytoplasm
Mitochondria
State the features found only in either a plant cell or an animal cell (4)
> Centrioles (animal)
> Cell wall (plant)
> Large central vacuole (plant)
> Chloroplast (plant)
State the formula for magnification
magnification = observed image size / actual size
triangle:
. . I . .
.A . M .
Define magnification
The number of times larger an image of an object is than the actual size of the object.
Define resolution
The ability to distinguish details between two objects very close together
Convert nano meter to micrometer to millimeter
1,000,000 nm -> 1000 um
1000 um -> 1mm
or:
(1,000 nm -> 1 um
1 um -> 0.001 mm)
Distinguish between an electron microscope and a light microscope
Electron microscope: Used to see things smaller than 200 nm. Has better resolution than a light microscope
Light microscope: Used to see things bigger than 200 nm. Can pick up colours using colour dyes.
Distinguish between a TEM (transmission electron microscope) and a SEM (scanning electron microscope).
TEM (transmission electron microscope): electrons go through the specimen, forms 2D images and produces a higher resolution in comparison to a SEM
SEM (scanning electron microscope): Scans specimen, forms 3D images and produces a lower resolution in comparison to a TEM
State the role of the nucleus (3)
stores DNA
production of rRNA
production of RNA (rRNA , tRNA, mRNA)
Describe the structure of the nucleus (4)
> Nuclear envelope
Nuclear pores
Nucleolus
Chromatin
What form does an uncondensed and condensed DNA take?
uncondensed: chromatin, loose and unpacked -> before cell division,
condensed: chromosome, packed and dense -> during cell division
Which ribosomes can be found in the mitochondria and chloroplast?
70s ribosomes
Which ribosomes can be found in the cytoplasm of eukaryotic cells and prokaryotic cells?
(nucleus) Eukaryotic: 80s
(no nucleus) Prokaryotic: 70s
Which microscope can ribosomes be seen with?
electron microscopes
Which 2 key components are ribosomes made up of?
rRNA and (ribosomal) proteins
differentiate between rRNA , tRNA and mRNA
rRNA: A major component of ribosomes
tRNA: Brings amino acids to ribosomes (to synthesise proteins)
mRNA: Carries genetic instructions from the DNA to the rest of the cell (ribosomes)
Differentiate between the rough ER and the smooth ER by structure
The rough ER has membrane-bound ribosomes, giving it a rough appearance, while the membrane-bound ribosomes are absent in the smooth ER.
State the function of the rough ER
Protein synthesis, modification and folding
State the function of the smooth ER (5)
Lipid synthesis
Steroid synthesis
Carbohydrate metabolism
Detoxification
Storing calcium ions
Describe the structure of the golgi apparatus
made up of a series of stacked, membrane-bound sacs called cisternae and forming a lumen. It has a cis face (receiving side) and a trans face (shipping side).
State the functions of the golgi apparatus (5)
> Lysosome synthesis
> Glycoprotein synthesis (sugar + protein)
> Glycolipid synthesis (sugar + lipid)
> Synthesis of polysaccharides (formation of new cell wall in plant cells)
> modifying, sorting, and packaging various biomolecules
State the enzymes found in lysosomes (5)
> Hydrolases
> Proteases
> Lipaseases
> Nucleases
> Lysozymes
State the function of lysosomes (3)
> Endocytosis: Digests materials taken into the cell
> Exocytosis: The lysosome may be released from the cell for extracellular digestion
> Self digestion: Lysosome contents are released into the cytoplasm for self digestion
-Autophagy: digestion of organelles (unnecessary or damaged)
-Apoptosis: digestion of the cell (cell death)
Describe the structure of the mitochondria (6):
> Double membrane (envelope)
> Outermembrane
> Innermembrane
> Intermembrane
> Cristae
> Matrix
(70s ribosomes and circular DNA can be found within the matrix.)
