Unicellular Marine Organisms

Chapter 4

The Cellular Structure of Life: Review • Cell wall: firm, fairly rigid

structure located outside the plasma membrane of plants, fungi, most bacteria, and some protists; provides support and protection.

• Plasma membrane: serves as boundary between the cell and its environment; allows materials such as water and nutrients to enter and waste products to leave.

The Cellular Structure of Life: Review cont.

• Cytoplasm: clear, gelatinous fluid in eukaryotic cells that suspends the cell’s organelles and is the site of numerous chemical reactions.

• Flagellum Flagella: long,

hairlike projections composed of pairs of microtubules; found on some cell surfaces; they help propel cells and organisms by a whiplike motion.

The Cellular Structure of Life: Review cont.

• Chromosome: a subcellular structure that contains the genetic information of the cell

• Nuclear membrane: the membrane surrounding the nucleus of eukaryotic cells

The Cellular Structure of Life: Review cont.

• Nucleus: the membrane-bound central structure of eukaryotic cells that contains the chromosomes

• Mitochondria: eukaryotic membrane-bound organelles that transform energy stored in food molecules into ATP has a highly folded inner membrane that produces energy-storing molecules.

The Cellular Structure of Life: Review cont.

• Endoplasmic reticulum: : organelle in eukaryotic cells with a series of highly folded membranes surrounded in cytoplasm; site of cellular chemical reactions; can either be rough (with ribosomes) or smooth (without ribosomes).

• Vacuoles: membrane-bond fluid –filled space in the cytoplasm of plant cells used for the temporary storage of materials.

The Cellular Structure of Life: Review cont.

• Lysosomes: attached to the vacuole and produce chemicals that digest the food stored inside it

• Golgi apparatus: releases or secretes important chemicals needed by the cells to carry out life functions.

The Cellular Structure of Life: Review cont.

• Chloroplasts: a subcellular structure containing chlorophyll, found in photosynthetic organisms

4.1 Classification:

• Taxonomy: the process of classifying organisms according to their evolutionary relationships

• Kingdom, Phylum, Class, Order, Family, Genius, Species

• Mnemonic Device to remember: King Philip came over for grape soda.

4.1 Classification: cont.

• The Five-Kingdom System: Monera, Protista, Fungi, Plantae, Animalia

4.1 Classification: cont.

The Five-Kingdom System: Monera, Protista, Fungi, Plantae, Animalia • Monera: Single-celled; lack

nuclear membrane (bacteria, blue-green bacteria) – Bacteria: Single-celled; lack

nuclear membrane – Prokaryotes: unicellular

organisms, such as bacteria composed of prokaryotic cells. Prokaryotic cells lack internal membrane-bond structures.

4.1 Classification: cont.

The Five-Kingdom System: Monera, Protista, Fungi, Plantae, Animalia • Protista: mostly single-celled,

some multicelled; have nuclear membrane (algae and protozoa – Unicellular: describes single-celled

organisms – Eukaryote: unicellular or

multicellular organisms, such as yeast, plants, and animals, composed of eukaryotic cells, which contain a true nucleus and membrane-bound organelles.

– Protozoa: animal-like organisms – Algae: plant like organisms

4.1 Classification: cont.

The Five-Kingdom System: Monera, Protista, Fungi, Plantae, Animalia

• Fungi: single-celled and multicelled; have nuclei; absorb food from living and dead organisms

4.1 Classification: cont.

The Five-Kingdom System: Monera, Protista, Fungi, Plantae, Animalia • Plantae: Multicelled; have

nuclei; make their own food through photosynthesis – Chlorophyll: light-

absorbing pigment in plants and some protista that is required for photosynthesis; absorbs most wavelengths of light except for green.

4.1 Classification: cont.

The Five-Kingdom System: Monera, Protista, Fungi, Plantae, Animalia

• Animalia: Multicelled; have nuclei; eat other organisms