Organelle Purpose & Shape

Rough ER Purpose

Builds proteins headed for secretion, membranes, or lysosomes, and keeps them separated from the cytosol.

Rough ER Shape

Folded, flattened sacks pack in lots of membranes from the RIBOSOMES to attach to.

Smooth ER Purpose

Makes lipids and detoxifies drugs and poisons. Lipids need membrane surface to be assembled on and detox is safer when contained.

Smooth ER Shape

Branched Tubes maximize membrane surface, where the lipid and detox enzymes are embedded. (NO RIBOSOMES)

Golgi Apparatus Purpose

Finishes, sorts, tags, and packages proteins from the ER into vesicles. The Golgi modifies and ‘natures’ proteins as they go through it.

Golgi Apparatus Shape

Stacked sacks let proteins be shaped and modified step by step, like an assembly line. One side is the entrance from the Rough ER, and the other side is the exit to other parts of the cell. (One directional movement)

Lysosome Purpose

Uses hydrolytic enzymes to digest worn-out organelles, engulfed material, and large molecules so their parts can be reused. (Essentially the trash can of the cell)

Lysosome Shape

Its membrane keeps the inside acidic (PH = 5) so the enzymes work, on it walls those enzymes off from the rest of the cell.

Vacuole Purpose

Stores water, nutrients, and waste, and in plants it keeps the plant rigid through water pressure. (Essentially the storage of a cell)

Vacuole Shape

The large central vacuole filled most of a plant cell and pushes against the cell wall.

Mitochondria Purpose

Carries out cellular respiration, converting glucose into ATP, the cells usable energy. Cells with high energy needs, like muscles and neurons, have many mitochondria. (Essentially the power generator of the cell)

Mitochondria Shape

Has double membrane which allows an H+ gradient that powers ATP production. The folded inner membrane allows for more surface area for more ATP making.

Chloroplast Purpose

Carries out photosynthesis, capturing energy/light from the sun to build sugar from CO2 and water. This sugar fuels the plant. (Essentially the power generator for plant cells)

Chloroplast Shape

Stacked thylakoids pack in membrane surface for chlorophyll to capture light.

Why are cells typically small?

Moving materials in and out of cells gets more difficult the larger the cell is. (Smaller surface area to volume ratio, the larger the ratio the more efficient the cell)

How do cells absorb adequate resources at a larger size?

Membrane folding allows for larger surface area to account for larger volume. Example (Root hairs for more water contact & Folding on the small intestine)