Chapter 4 Vocab Flashcards
Bacterial Chromosome
DNA in a bacterial cell
Capsule
The protein shell that encloses a viral genome
Cell wall
A protective layer external to the plasma membrane in plant cells, bacteria, fungi, and some protists; protects the cell and helps maintain its shape
Central Vacuole
In a plant cell, a large membranous sac with diverse roles in growth and the storage of chemicals and wastes
Centriole
A structure in an animal cell composed of cylinders of microtubule triplets arranged in a 9 + 0 pattern. An animal usually has a centrosome with a pair of centrioles involved in cell division
Chloroplast
An organelle found in plants and photosynthetic protists that absorbs sunlight and uses it to drive the synthesis of organic molecules (sugars) from carbon dioxide and water
Chromatin
The combinations of DNA and proteins that constitutes eukaryotic chromosomes; often used to refer to the diffuse, very extended form taken by chromosomes when a cell is not dividing
Cytoskeleton
A network of protein fibers in the cytoplasm of a eukaryotic cell; includes microfilament, intermediate filaments, and microtubules
Fimbraie
One of the short, hairlike projections on some prokaryotic cells that help attach the cells to their substrate or to other cells
Flagella
A long cellular appendage specialized for locomotion. The flagella of prokaryotes and eukaryotes differ in both structure and function. Like Cilia, eukaryotic flagella have a 9 + 2 arrangement of microtubules covered by the cell’s plasma membrane
Golgi Apparatus
An organelle in eukaryotic cells consisting of stacks of membranous sacs that modify, store, and ship products of the endoplasmic reticulum
Intermediate fibers
An intermediate-sized protein fiber that is one of the three main kinds of fibers making up the cytoskeleton of eukaryotic cells. Intermediate filaments are ropelike, made of fibrous proteins
Lysosome
A digestive organelle in eukaryotic cells; contains hydrolytic enzymes that digest engulfed food or damaged organelles
Microfilament
The thinnest of three main kinds of protein fibers making up the cytoskeleton of a eukaryotic cell; a solid, helic rod composed of the globular protein actin
Microtubule
The thickest of the three main kinds of fibers making up the cytoskeleton of a eukaryotic cell; a hollow tube made of globular proteins called tubulins; found in cilia and flagella
Mitochondria
An organelle in eukaryotic cells where cellular respiration occurs. Enclosed by two membranes, it is where most of the cell’s ATP is made
Nuclear Envelope
A double membrane that encloses the nucleus, perforated with pores that regulate traffic within the cytoplasm
Nucleoid
A dense region of DNA in a prokaryotic cell
Nucleolus
A structure within the nucleus where ribosomal RNA is made and assembled with proteins imported from the cytoplasm to make ribosomal subunits
Nucleus
(1.) An atom’s central core, containing protons and neutrons
(2.) The genetic control center of a eukaryotic cell
Perioxisome
An organelle containing enzymes that transfer hydrogen atoms from various substrates to oxygen, producing and then degrading hydrogen peroxide
Plasma Membrane
The membrane t the boundary of every cell that acts as a selective barrier to the passage of ions and molecules into and out of the cell; consists of a phospholipid bilayer with embedded proteins
Plasmodesma
An open channel in a plant cell wall through which strands of cytoplasm connect from adjacent cells
Ribosome
A cell structure consisting of RNA and protein organized into two subunits and functioning as the site of protein synthesis in the cytoplasm. In eukaryotic cells, the ribosomal subunits are constructed in the nucleolus
Rough endoplasmic reticulum
That portion of the endoplasmic reticulum with ribosomes attached that make membrane proteins and secreory proteins
Smooth endoplasmic reticulum
That portion of the endoplasmic reticulum that lacks ribosomes
