cell structure (eukaryotic) Flashcards
Cell-surface membrane: structure
Phospholipid bilayer with proteins and cholesterol embedded within it. Glycolipids and glycoproteins in the surface.
Cell-surface membrane: function
The fluid-mosaic model of the membrane refers to the fluidity and range of molecules in the membrane. Cholesterol provides strength and reduces fluidity, proteins are for transport and the glycoproteins and glycolipids are for cell recognition and act as receptors.
Nucleus: structure
Surrounded by a double membrane nuclear envelope with nuclear pores. Containing chromosomes, consisting of protein-bound, linear DNA, and one or more nucleolus
Nucleus: function
Nucleolus is the site of rRNA product and makes ribosomes. DNA replication and transcription occur in the nucleus.
Mitochondria: structure
Double membrane organelle. The inner membrane is folded to form cristae. Contains a fluid centre called the matrix
Mitochondria: function
Site of aerobic respiration and ATP production.
Chloroplasts: structure
Surrounded by a double membrane. Contains thylakoids, which are folded membrane containing chlorophyll pigments. Contains a fluid centre, the stroma.
Chloroplasts: function
The site of photosynthesis. The stroma contains enzymes for the light-independent stage of photosynthesis.
Golgi apparatus and Golgi vesicles: structure
Stacks of membranes creating flattened sacs called cisternae, surrounded by small round hollow vesicles.
Golgi apparatus and Golgi vesicles: function
Proteins and lipids and modified here. Carbohydrates can be added to proteins to form glycoproteins. Finished products are transported in the Golgi vesicles.
Lysosomes: structure
Formed when the Golgi apparatus contains hydrolytic enzymes.
Lysosomes: function
A type of Golgi vesicle that releases lysozymes.
Ribosomes: structure
Small granules in cells made of protein and rRNA. Made up of a small and large subunit. 80s in size in eukaryotes (70s in prokariotes).
Ribosomes: function
The site of translation in protein synthesis.
Rough endoplasmic reticulum (RER): structure
Sheets of membranes linked to the nucleus. The membranes form a network of cisternae - a network of tubules and flattened sacs, with ribosomes on the outer surface.
Rough endoplasmic reticulum (RER): function
RER- site of protein synthesis and glycoprotein synthesis. The proteins can then be transported through the RER.
Smooth endoplasmic reticulum (SER): structure
Sheets of membranes linked to the nucleus. The membranes form a network of cisternae - a network of tubules and flattened sacs.
Smooth endoplasmic reticulum (SER): function
SER – create, store and transport lipids and carbohydrates.
Cell wall (eukaryotes): structure
Found in plants, algae and fungi. Consists of polysaccharides, cellulose in plants and chitin in fungi. There is a thin boundary layer between adjacent cells called the middle lamella.
Cell wall: function
Provides structural strength to cells and prevents cells from bursting when water enters by osmosis.
Large, permanent Vacuole: structure
Found in plants. A single membrane sac filled with fluid containing salts, sugars and amino acids. The membrane around a cell vacuole is called the tonoplast.
Large, permanent Vacuole: function
To provide support to a cell, store amino acids and sugars and can contain pigments to attract pollinators.
Cytoskeleton: structure
Found within the cytoplasm all over a cell.
Cytoskeleton: function
Provides mechanical strength to cells, helps with transport within cells and allows cell movement. Many organelles are bound to the cytoskeleton
