Organisation of Life Flashcards
1
Q
How big are different types of cells?
A
- Prokaryotic cells ~ 1-5um
- Eukaryotic cells ~ 10-100um
2
Q
Why is cell surface area to volume ratio important?
A
- Want a high surface area to volume ratio
- Exchanging molecules with the external environment
- Increasing internal SA for biochemical reactions
3
Q
What is the nucleus?
A
- Nuclear material surrounded by the double lipid bilayer nuclear
- Substances travel in handout through nuclear pores
- Genetic information is stored as chromatin: DNA wrapped around proteins (histones)
- Nucleolus makes ribosomal components: rRNA and ribosomal proteins which are exported into the cytoplasm
4
Q
What are ribosomes?
A
- Synthesise proteins from amino acids by following mRNA instructions and translating it into proteins
- Made of rRNA and protein: a small subunit and a large subunit
- Free ribosomes are found in the cytosol: making cytosolic proteins
- Bound ribosomes are associated with the ER: make proteins for membranes, export and some organelles
5
Q
What is the endomembrane system made up of?
A
- Series of interconnected membrane-bound organelles NERVGVLP - Nuclear envelope - Endoplasmic reticulum (smooth and rough) - Vesicles - Golgi apparatus - Vacuoles - Lysosomes - Plasma membrane
6
Q
What is the smooth ER?
A
- Tubular structure
- No associated ribosomes
LCD - Lipid synthesis
- Ca2+ storage
- Detoxification
7
Q
What is the rough ER?
A
- Continuous with the outer nuclear membrane
- Has associated ribosomes
- Makes and modifies proteins
8
Q
What is the golgi apparatus?
A
- Layers of flattened single phospholipid bilayer membranous sacs
- Receives vesicles at cis face
- May further modify proteins from the ER
- Each sac has a different set of enzymes e.g. add sugars or cut proteins
- Ships vesicles from trans face
- Targets vesicles towards organelles or plasma membrane
9
Q
How is the endomembrane system connected?
A
- Physical continuity
- Vesicle traffic: budding (sending) and fusing (receiving)
10
Q
What are lysosomes?
A
- Membranous sacs containing digestive enzymes made by the RER that arrive via the golgi
- Hydrolyse macromolecules
- Food vacuole digestion: provides nutrients
- White blood cells: engulf bacteria
- Autophagy: digestion of organelles
11
Q
What are vacuoles?
A
- Large fluid filled vesicles SLyCC - Storage vacuole (proteins, pigments) - Lytic vacuoles (like lysosomes) - Central vacuole - Contractile vacuole
12
Q
What is fluorescence microscopy?
A
- Chlorophyll glows red when exposed to blue light
- Confocal microscopy captures fluorescent lights at a plane of focus creating a very clear image of cellular structures
13
Q
What is the function of the cytoskeleton?
A
SAM
- Structure and support
- Anchorage
- Motility
14
Q
What are the types of fibres in the cytoskeleton?
A
MIM
- Microfilaments
- Intermediate filaments
- Microtubules
15
Q
What are the functions of microfilaments?
A
MSND
- Muscle cell contraction
- Cytoplasmic streaming
- Network in plasma membrane to maintain shape
- Animal cell division
