2.1 Cell Structure Flashcards
What are plasmodesmata?
Channels/holes in a plant cell walls to allow exchange with adjacent cells
What are plant cell walls made of?
Cellulose (β-glucose polymer)
What are fungi cell walls made of?
Chitin (polysaccharide)
What are bacteria cell walls made of?
Murein (glycoprotein polymer)
Differences between plant and animal cells
- Plasmodemata
- Chloroplast
- Vacuole
- Cell wall
Nucleoulus funtion
Production of ribosomes
What are ribosomes made of?
rRNA and proteins - 80s and 70s have different protein subunits
Nucleus structure
Nuclear envelope with many nuclear pores surrounding chromosomes and nucleoli
Nucleus function
- House DNA
- Site of transcription of DNA into mRNA to produce proteins
- House nucleoli
Mitochondria structure
Oval shaped, double membrane, inner membrane folded to form cristae, matrix inside with enzymes, ribosomes and genetic information
Golgi apparatus structure
Groups of fluid filled, membrane bound flattened sacs
Golgi apparatus function
- Process and package new lipids and proteins
- Produce lysosomes
RER structure
System of fluid filled space, membrane bound and covered with ribosomes
RER function
Folds and process proteins produced at attached ribosomes
SER structure
System of fluid filled space, membrane bound
SER function
Synthesise and process lipids
Lysozyme structure
Round, membrane bound, no clear internal structures, filled with lysozymes
Cell vacuole structure
Tonoplast membrane surrounding cell sap
- Cell sap = soln of sugar and salts
3 functions of cell vacuole
- Maintain pressure in cell ∴ rigidity
- Prevents cell wilting
- Isolates unwanted chemicals in cell
Chloroplast structure
Flattened structure, double membrane, thick stroma, thylakoid membranes inside, thylakoids stacked into grana which are linked with lamellae (thin flat membrane extensions)
Which types of cell photosynthesise?
Plant cells + algae
Eukaryote DNA description
Linear-DNA which is histone/protein bound
Prokaryote DNA description
Circular DNA in one long coiled strand not protein associated
3 prokaryote only features
- Plasmids (multiple?/0) (short loops of DNA not a part of main circular DNA molecule)
- Flagella (multiple?/0)
- Capsule made of secreted slime
Virus structure
No plasma membrane, no cytoplasm, no ribosomes
Core genetic material surrounded by protein coat/capsid with attachment proteins
Binary fission in prokaryotes steps (4)
1) Circular DNA strand and plasmids replicate
2) Cell gets bigger and the 2 circular DNA strands move to opposite poles of cell
3) Cytoplasm divides and new cell wall forms
4) 2 daughter cells with identical circular DNA formed and variable plasmid numbers
Virus replication
1) Virus attaches to host cell using attachment proteins complementary to receptor proteins
2) Virus injects core genetic material into host cell which replicates viral particles
