Cell structure Flashcards
What is a eukaryotic cell?
Cell where the DNA is contained in nucleus and membrane-bound organelles
What is a prokaryotic cell?
DNA is free in cytoplasm and no organelles
Describe the structure of nucleus
- Nuclear envelope: Double membrane controls what enters and exits
- Nuclear pores: Allows large molecules out
- Nucleolus: Small sphere makes rRNA/ribosomes
- Nucleoplasm: Granular jelly-like material fills nucleus space
- Chromosomes: Protein bond linear DNA
Function of nucleus
- Site of DNA replication
- Site of mRNA/tRNA/rRNA/ribosome production
- Contains genetic material of cell
Describe the structure of mitochondria
- Double membrane: Controls entry and exit
- Cristae: Extension of inner membrane = large SA for respiration enzymes
- Matrix: Respiratory enzymes + proteins + lipids
- Mitochondrial DNA: Loop of DNA to produce own proteins
Function of mitochondria
- Site of aerobic respiration
- Site of production of ATP
- DNA codes for enzymes needed in respiration
Describe the structure of chloroplast
- Double membrane: Controls entry and exit
- Thylakoid: Folded membrane disks containing chlorophyll stack up to make grana
- Grana: Large surface area for chlorophyll + proteins for LDR
- Lamellae: Tubular extensions that attach thylakoids to adjacent grana
- Stroma: Fluid filled matrix with enzymes for LIR
- DNA/Ribosomes: To produce own proteins
Function of chloroplast
- Site for photosynthesis
Describe structure of endoplasmic reticulum
- Cisternae: Tubules and flattened sacs from cell membrane and connected to nuclear envelope
RER: - Ribosomes attached for large SA for protein synthesis
SER: - No ribosomes and more tubular structure
Function of endoplasmic reticulum
RER:
- Protein synthesis
- Transport of protein
SER:
- Synthesis/store/transport of lipids and carbs
Describe the structure of Golgi apparatus
- Cisternae: Stack of membrane bound flattened sacks
- Secretory vesicles: Small rounded structure that pinch off membranes
Function of Golgi apparatus
- Adds carbs to proteins to make glycoproteins
- Modify/transport/store lipids
- Produce lysozomes
Describe the structure of lysozomes
Single membrane sack containing lysozyme/hydrolyzing enzymes
Function of lysozome
- Hydrolyzes phagocytic cells
- Autolysis
- Exocytosis
- Hydrolyze worn out organelles for re-use
Describe the structure of ribosomes
- Made of a small + large subunits of protein and rRNA
- 80s: Large ribosome in eukaryotic cells
- 70s: small ribosomes in prokaryotic cells, mitochondria, chloroplasts
Function of ribosomes
- Site of protein synthesis
Describe structure of cell wall
- Plants: Made of cellulose
- Fungi: Made of chitin
- Bacteria: Made of murein
Function of cell wall
- Gives cell mechanical strength so it doesn’t burst under pressure during osmosis
- Barrier
- Structural support