chapter 4 Bio: Cell Structure

Eukaryotic Cilia and Flagella

are long, hair-like structures that extend from the plasma membrane and are used to move an entire cell. When cilia (singular = cilium) are present, however, many of them extend along the entire surface of the plasma membrane. They are short, hair-like structures that are used to move entire cells (such as paramecia) or substances along the outer surface of the cell

Chloroplasts

are plant cell organelles that carry out photosynthesis. Photosynthesis is the series of reactions that use carbon dioxide, water, and light energy to make glucose and oxygen.

Mitochondria

are responsible for making adenosine triphosphate, the cells main energy-carrying molecule.

Peroxisomes

are small, round organelles enclosed by single membranes. They carry out oxidation reactions that break down fatty acids and amino acids. They also detoxify many poisons that may enter the body.

The lysosomes

are the cell's "garbage disposal." Found in animal cells, but not plant cells.

Intermediate Filaments of the cytoskeleton

have no role in cell movement. Their function is purely structural. They bear tension, thus maintaining the shape of the cell, and anchor the nucleus and other organelles in place

the plant cell wall

is cellulose, a polysaccharide made up of glucose units.

Actin filaments

is powered by ATP to assemble its filamentous form, which serves as a track for the movement of a motor protein called myosin. This enables actin to engage in cellular events requiring motion, such as cell division in animal cells and cytoplasmic streaming, which is the circular movement of the cell cytoplasm in plant cells.

Central Vacuole

plays a key role in regulating the cell's concentration of water in changing environmental conditions.

1. What are the four parts or regions of the cell that are present in EVERY cell (prokaryotic AND eukaryotic)?

All cells share four common components: 1) a plasma membrane, an outer covering that separates the cell's interior from its surrounding environment; 2) cytoplasm, consisting of a jelly-like cytosol within the cell in which other cellular components are found; 3) DNA, the genetic material of the cell; and 4) ribosomes, which synthesize proteins.

Golgi Apparatus

Sorting, tagging, packaging, and distribution of lipids and proteins takes place in the Golgi apparatus (also called the Golgi body), a series of flattened membranes

Identify structures that ALL EUKARYOTIC cells have

Plasma Membrane Cytoplasm Nucleolus Nucleus Ribosomes Mitochondria Peroxisomes Vesicles and vacuoles Endoplasmic Reticulum Golgi Apparatus Cytoskeleton

Identify structures that ALL cells have

Plasma Membrane Cytoplasm Ribosomes Cytoskeleton

2. Where is DNA located in a prokaryote?

Prokaryotic DNA is found in a central part of the cell: the nucleoid

3. What reason does your book give for why prokaryotic cells are so much smaller than eukaryotic cells?

The small size of prokaryotes allows ions and organic molecules that enter them to quickly diffuse to other parts of the cell

Ribosomes

are the cellular structures responsible for protein synthesis

Microtubules

are the widest components of the cytoskeleton. They help the cell resist compression, provide a track along which vesicles move through the cell, and pull replicated chromosomes to opposite ends of a dividing cell.

Chromatin

are unwound protein-chromosome complexes

Be able to identify structures that are unique to plant eukaryotic cells

cell wall: cellulose Chloroplasts

a) Nucleus

houses the cell's DNA and directs the synthesis of ribosomes and proteins.

The nuclear envelope

is a double-membrane structure that constitutes the outermost portion of the nucleus. Both the inner and outer membranes of the nuclear envelope are phospholipid bilayers.

Endoplasmic Reticulum: rough and smooth

is a series of interconnected membranous sacs and tubules that collectively modifies proteins and synthesizes lipids.