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Functions of the smooth ER

Synthesizes lipids (including oils, phospholipids, and steroids), metabolizes carbohydrates, detoxifies drugs and poisons (especially in liver cells), and stores calcium ions (important in muscle cells for contraction).

Mitochondria

Main parts include the outer membrane, inner membrane, cristae (folds), and matrix.

Chloroplasts

Main parts include the outer membrane, inner membrane, thylakoids (stacks called grana), and stroma.

Function of motor proteins

Motor proteins like kinesin and dynein help transport materials within cells by moving along the cytoskeleton (microtubules and actin filaments). They play roles in cell division, intracellular transport, and muscle contraction.

Five cell structures common to prokaryotes and eukaryotes

Plasma membrane, cytoplasm, ribosomes, DNA (though it's stored differently), and cell wall (present in plants and bacteria).

Four pieces of evidence for the endosymbiosis theory

Mitochondria and chloroplasts have their own DNA similar to prokaryotes, replicate by a process similar to binary fission, have double membranes, and have their own ribosomes, which are similar to those found in prokaryotes.

RNA world hypothesis

The RNA world hypothesis suggests that early life forms may have relied solely on RNA for genetic information and catalysis before the evolution of DNA and proteins.

Supporting evidence for RNA world hypothesis

RNA's ability to both store genetic information and catalyze chemical reactions (ribozymes).

Why is rough ER rough?

The rough ER is "rough" because it is studded with ribosomes on its surface.

Function of rough ER

Its main function is to synthesize proteins, especially those destined for secretion or for use in membranes.

Ribosomes

Ribosomes are made of ribosomal RNA (rRNA) and proteins. They have two subunits: a large subunit and a small subunit.

Locations of ribosomes in a plant cell

Free in the cytoplasm, attached to the Rough ER, inside mitochondria, and inside chloroplasts.

Importance of compartmentalization in eukaryotes

Compartmentalization allows for different metabolic processes to occur in separate organelles, increasing efficiency and enabling specialized functions.

Examples of proteins synthesized by ribosomes bound to the rough ER

Insulin (a secretory protein) and membrane proteins like ion channels or receptors (e.g., sodium-potassium pump).

Stanley Miller's experiment

Stanley Miller is famous for the Miller-Urey experiment, which simulated early Earth conditions to test the chemical origins of life.

Recent changes to Miller's experiment view

More recent experiments suggest that different conditions (e.g., volcanic gases) could have also contributed to the formation of organic molecules.

Commonality of microvilli, alveoli, and glomeruli

They all increase surface area to optimize function.

Main parts of the endomembrane system

The nuclear envelope, endoplasmic reticulum (rough and smooth), Golgi apparatus, lysosomes, vesicles, and plasma membrane.

Function of the endomembrane system

Its main function is to synthesize, modify, package, and transport proteins and lipids within the cell and to the cell surface for secretion.

Path of secreted protein from synthesis to secretion

The process starts with protein synthesis on ribosomes bound to the rough ER, followed by transport into the lumen of the rough ER, packaging into vesicles, processing in the Golgi apparatus, and finally secretion via exocytosis.

Purpose of cell fractionation

Cell fractionation allows a biologist to isolate different components of the cell (like organelles) to study their specific functions.