Cell structure part 2 Flashcards
What’s a eukaryotic cell?
Cells that have a nucleus inside a nuclear envelope, and other membrane-bound organelles
What’s ultrastructure?
The detailed structure of the internal components of cells as revealed as revealed by the electron microscope, rather than by the light microscope
3 similarities between an animal cell and a plant cell?
Both have nucleus, plasma membrane, cytoplasm
3 differences between animal and plant cell?
Only plants have cell wall, vacuoles and chloroplast
Label a mitochondrion
Outer membrane- basically outside layer of organelle
Inner membrane- Bit of matrix nearly up against outer membrane
Intermembrane space- space between inner and outer membrane
Cristae- top/curved bit of matrix
Matrix- main wiggly bit in middle
2-5 um long
Label a chloroplast
inner membrane
Outer membrane- outer shell of organelle
intermembrane compartment- between outer and inner membrane
Granium- large cylinder
Thylakoids- disks in cylinder
Stroma- space in organelle
Intergranal lamellae- link graniums together
4-10 um long
Flow chart showing how different organelles and molecules are involved in the process of protein production and trafficking in the cell? Eg. insulin
The instructions to make the insulin hormone are found in the DNA in the nucleus
The specific instructions to make the insulin hormone is known as the gene for that hormone. Genes are found in the chromosome in the nucleus
The nucleus copies the instructions in the DNA into a molecule called mRNA, this is transcription
The mRNA molecule leaves the nucleus through a nuclear pore and attaches to a ribosome, in this case the ribosome is attached to the RER
Ribosome reads the instructions and uses the code to assemble to assemble the insulin protein, this is translation
The assembled protein inside the RER is pinched off into a transport vesicle and transported to the Golgi apparatus
The Golgi apparatus packages the insulin protein, and may also modify it so that it is ready for secretion
The insulin protein is now packaged into a secretary vesicle, and moved to plasma membrane
The secretory vesicle fuses with the plasma membrane and exocytosis takes place. Insulin enters the blood stream
What are the 3 types of cytoskeleton filaments?
Actin filaments (microfilaments)
Intermediate filaments
Microtubules
Structure of actin filaments?
Strands in double helix
Subunit is actin
7nm width
Structure of intermediate filaments?
Fibres wound into thick cables
Subunit is keratin
width is 10nm
Structure of microtubules?
Hollow tube
subunit is alpha and beta tubulin dimers
Function of actin filaments?
Maintains cell shape by pulling
Moves cells via muscle contraction or cell crawling
Divides animals cells in 2
Move organelles and cytoplasm
Function of intermediate filaments?
Maintain cell shape by pulling
Anchor nucleus and some other organelles
Function of microtubules?
Maintains cell shape by pushing Moves cells via flagella or cilia Moves chromosomes during cell division Moves organelles Provides tracks for intercellular transport
What do cilia and flagella contain?
2 central microtubules, and 9 outer microtubules these enable movement
