5.3 Internal Organization of Cells

A bacterial cell, a plant cell, and an animal cell have which structure in common? A) a cytoplasm B) a vacuole C) a nucleoid D) a cell wall E) a nucleus

A) a cytoplasm

All cells have: A) genetic information B) a cell wall C) internal compartments D) a nucleus

A) genetic information

Plasmids

in bacteria, a small circular molecule of DNA carrying a small number of genes that replicate independently of the DNA in the bacterium's circular chromosome

Nucleoid

in prokaryotes, a cell structure with multiple loops formed from supercoils of DNA

How do eukaryotic plant and animal cells differ from one another? A) Animal cells have mitochondria but not chloroplasts, and plant cells have chloroplasts but not mitochondria. B) Animal cells have endoplasmic reticulum, and plant cells don't. C) Animal cells do not have chloroplasts and cell walls, and plant cells do. D) Animals cells have a plasma membrane, and plant cells have a cell wall.

C) Animal cells do not have chloroplasts and cell walls, and plant cells do. *Because both plants and animals must perform cellular respiration, they both require mitochondria.

Which eukaryotic organelle is associated with the breakdown of macromolecules? A) mitochondria B) endoplasmic reticulum C) the Golgi apparatus D) lysosome

D) lysosome

Which eukaryotic cell structure plays a role in protein trafficking and sorting? A) lysosomes B) mitochondria C) vacuoles D) the Golgi apparatus E) peroxisomes

D) the Golgi apparatus

Compare the organization, degree of compartmentalization, and size of prokaryotic and eukaryotic cells.

Prokaryotic cells lack a nucleus and extensive internal compartmentalization. They contain plasmids that carry additional genes that can be transferred to other bacteria. Prokaryotic cells are small (usually 1-2 micrometers in diameter or smaller). Because of their small size, they have a large surface-area-to-volume ratio, which means they are able to absorb nutrients from the environment to meet their metabolic needs. Eukaryotic cells have a nucleus and specialized internal structures called organelles. They are 10 times larger in diameter and 1000 times larger in volume than a prokaryotic cell.

Pili (Pilus)

a hollow, threadlike structure that connects bacteria, allowing plasmids to be transferred between them in the process of conjugation

Chloroplasts

an organelle in photosynthetic eukaryotes that converts energy of sunlight into chemical energy by synthesizing simple sugars

Prokaryote

an organism whose cell or cells do not have a membraned-bound nucleus; sometimes used to refer collectively to archaeons and bacteria

Eukaryote

an organism whose cells have a true nucleus

Organelles

any one of several compartments in eukaryotes that divide the cell contents into smaller spaces specialized for different functions

Nucleus

the compartment of the cell that houses the DNA in chromosomes

Cytoplasm

the contents of the cell other than the nucleus

Cytosol

the region of the cell inside the plasma membrane but outside the organelles; the jelly-like internal environment that surrounds the organelles.