Honors Biology - Chapter 4

Lysosomes

A digestive organelle in eukaryotic cells; contains hydrolytic enzymes that digest engulfed food or damaged organelles.
Extra Info:

* _______ are derived from two Greek words meaning "breakdown body"
* Enzymes and membranes are made from Rough ER
* Have several digestive functions

Plasmodesma

An open channel in a plant cell wall that connects the cytoplasm of adjacent cells.

Glycoprotien

A protein with one or more short chains of sugar attached.

Sugars

________ are made in the stroma by the enzymes of the Calvin cycle.

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.

Nucleoid

A non-membrane-bounded region in a prokaryotic cell where the DNA is concentrated.

Microfilaments

The thinnest of the three main kinds of protein fibers making up the cytoskeleton of a eukaryotic cell; a solid, helical rod composed of the globular protein actin.

Mitochondria

An organelle in eukaryotic cells where cellular respiration occurs.

Peroxisome

An organelle containing enzymes that transfer hydrogen atoms from various substrates to oxygen, producing and then degrading hydrogen peroxide.

Extracellular matrix (ECM)

The meshwork surrounding animal cells; consists of glycoproteins and polysaccharides synthesized and secreted by cells.

Endomembrane system

A network of membranes inside and surrounding a eukaryotic cell, related either through direct physical contact or by the transfer of membranous vesicles.

Integrin

A transmembrane protein that interconnects the extracellular matrix and the cytoskeleton in animal cells.

Golgi Enzymes

Modify the carbohydrate portions of the glycoproteins made in ER.

Cytosol

The semifluid portion of the cytoplasm.

Golgi appartus

An organelle in eukaryotic cells consisting of stacks of membranous sacs that modify, store, and ship products of the endoplasmic reticulum.

Serves:

*  As a warehouse and processing station for ER products

Cilia

 A type of protist that moves and feeds by means of cilia. Ciliates belong to the alveolate clade of the SAR supergroup. Cilia and FLAGELLA have common structures and mechanisms of movement.

Endoplasmic reticulum

An extensive membranous network in a eukaryotic cell, continuous with the outer nuclear membrane and composed of ribosome-studded (rough) and ribosome-free (smooth) regions.

Flagellum

A long cellular appendage specialized for locomotion.

Centrosome

A structure found in animal cells from which microtubules originate and that is important during cell division.

Cytoskeleton

A network of protein fibers in the cytoplasm of a eukaryotic cell; includes microfilaments, intermediate filaments, and microtubules.

Stroma

The dense fluid within the chloroplast that surrounds the thylakoid membrane.

Chloroplast

An organelle found in plants and algae that absorbs sunlight and uses it to drive the synthesis of organic compounds (sugars) from carbon dioxide and water.

Organelles

A membrane-enclosed structure with a specialized function within a cell.

Cytoplasm

The contents of a eukaryotic cell between the plasma membrane and the nucleus; consists of a semifluid medium and organelles; can also refer to the interior of a PROKARYOTIC cell. In EUKARYOTIC cells this term refers ONLY to the region between the nucleus and plasma membrane

Primary cilium

Is important to embryonic development, sensory reception, and cell function.

Chromosome

a gene-carrying structure found in the nucleus of a eukaryotic and most visible during mitosis and meiosis; also, the main gene-carrying structure of a prokaryotic cell.

Transport Vesicles

A small membranous sac in a eukaryotic cell's cytoplasm carrying molecules produced by the cell. The vesicle buds from the endoplasmic reticulum or Golgi and eventually fuses with another organelle or the plasma membrane, releasing its contents.

Thylakoid space

The compartments inside the thylakoids.

Thylakoid

A flattened membranous sac inside a chloroplast.

Rough endoplasmic reticulum

The portion of the endoplasmic reticulum with ribosomes attached that make membrane proteins and secretory proteins.

Mitochondrial matrix

The compartment of the mitochondrion enclosed by the inner membrane and containing enzymes and substrates for the citric acid cycle.

Ribosome

A cell structure consisting of RNA and proteins 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 NUCLEUS.

Vacuole

A membrane-enclosed sac that is part of the endo-membrane system of a eukaryotic cell and has diverse functions in different kinds of cells.

Light Microscope (LM)

Optical instrument with lenses that refract (bend) visible light to magnify images and project them into the viewer's eye or onto photographic film. These can be used to study live specimens, but they only magnify about a thousand times.

Endosymbiont theory

The theory that mitochondria and chloroplasts originated as prokaryotic cells engulfed by an ancestral eukaryotic cell. The engulfed cell and its host cell then evolved into a single organism.

Intermediate filaments

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.

What it does:

* Reinforces cell shape and anchors some organelles. Also are more often permanent fixtures in the cell.

Tight junctions

____, the plasma membranes of neighboring cells are knit tightly together by proteins. ____ prevent leakage of fluid across a layer of cells.

Phospholipids

A lipid made up of glycerol joined to two fatty acids and a phosphate group, giving the molecule two non- polar hydrophobic tails and a polar hydrophilic head.

Plasma membrane

The membrane at 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 (also referred to as cell membranes)

Electron Microscope (EM)

A microscope that uses magnets to focus an electron beam on or through a specimen, resulting in resolving power a thousandfold greater than that of a light microscope

Scanning Microscope (SEM)

A microscope that uses an electron beam to study the surface details of a cell or other specimens

Transmission Electron Microscope (TEM)

A microscope that uses an electron beam to study the internal structure of thinly sectioned specimens

Cell Theory

the idea that all living things are composed of cells, cells are the basic units of structure and function in living things, and new cells are produced from existing cells

Prokaryotic Cells

Were the first to evolve, are simpler, and are usually smaller than eukaryotic cells (Earth's sole inhabitants for 1.5 billion years)

Eukaryotic Cells

A type of cell that has a membrane-enclosed nucleus and membrane-enclosed organelles

Chromosome

a gene-carrying structure found in the nucleus of a eukaryotic and most visible during mitosis and meiosis; also, the main gene-carrying structure of a prokaryotic cell

Glycoprotien

A protein with one or more short chains of sugar attached

Free Ribosomes

Are suspended in cytosol, structurally identical to BOUND ribosomes and can function in either location, depending on the protein their making

Bound Ribosomes

Are attached to the outside of the endoplasmic reticulum or nucleus envelope

Central Vacuole

In a plant cell, a large membranous sac with diverse roles in growth and the storage of chemicals and wastes

Anchoring Junctions

____ function like rivets, fastening cells together into strong sheets

Gap Junctions

Gap junctions, also called communicating junctions, are channels that allow small molecules to flow through protein-lined pores between cells

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

Smooth Endoplasmic Reticulum

The portion of the endoplasmic reticulum that lacks ribosomes. Also storages calcium ions