cell structure
Cards (14)
- mitocondria have a double membrane, cristae structures, and a matrix
- chloroplasts have an outer membrane, thylakoid membranes stacked together as grana, starch granules store excess glucose made during photosynthesis
- cell fractionation and ultracentrifugation:
- Homogenise cells to break them open and release organelles
- Filter to remove debris
- Ice Cold solution to prevent enzyme activity
- Isotonic solution to prevent osmosis
- PH Buffered solution to stop enzymes denaturing
- spin at low speed so nuclei in pellet can be removed
- continue until required organelle is in pellet
- the phospholipid bilayer has a hydrophobic tail and hydrophilic head in order to form a barrier for water soluble substances, allowing small, non-polar molecules through
- mitochondria are double membrane bound organelles that are the site of aerobic respiration, they have a highly folded inner membrane creating a cristae (for a high SA)
- ribosomes are made of RNA and proteins and are found in the cytoplasm, they can be free floating or attached to RER
- lysosomes are single membrane bound organelles that contain hydrolytic enzymes that digest and recycle materials
- peroxisomes contribute to cellular function by hydrolysing fatty acids
- viruses are acellular, they consist of nucleic acids surrounded by proteins
- in the phospholipid bilayer cholesterol maintains fluidity and also restricts the movement of other molecules.
- Rough endoplasmic reticulum is a series of flattened sacs enclosed by a membrane with ribosomes on the surface. it folds and processes proteins made on the ribosomes.
- Smooth endoplasmic reticulum is a system of membrane bound sacs. it produces and processes lipids.
- golgi apparatus is a series of fluid filled, flattened & curved sacs with vesicles surrounding the edges. Golgi apparatus processes and packages proteins and lipids. It also produces lysosomes.
- Capsule (prokaryotic cell) – Protective slimy layer which helps the cell to retain moisture and adhere to surfaces.