Cytoplasmic streaming in as single Spirogyra cell
This is a single green alga cell, from the genus Spirogyra. Spirogyra gets its name because inside each cell is a ribbon-like green chloroplast that coils and gives the cell its spiral appearance. Cells are filled with cytoplasm–a clear water-based fluid packed with proteins, nutrients and vesicles–that constantly circulated in the cell to keep all its contents moving and distributed around the entire space. In a big algal cell like this one you can see cytoplasmic streaming in action.
Phagocytosis - Collodictyon triciliatum
A single cellular predator, Collodictyon tricilatum seeks out and eats two green algae cells. Yum. This video is sped up six times, total process takes roughly six minutes.
Phagocytosis - An amoeba from the salt marsh in Brooklyn.
This little character is an amoeba. It's shaped like a blob. Amoebas are predators, they need to eat to survive. In this clip, you can see it trying to eat a long alga. The alga is far too long to fit inside the amoeba, and sure enough (after a thorough investigation) the amoeba gives up on its lunch. This clip is sped up four times, so covers about four minutes in real-time. Amoebas are slow.