(E) Chapter 4: Cell structure

Actin

Actin is a globular multi-functional protein that forms microfilaments.

Transfer RNA

Carries amino acids.

Messenger RNA

Carries coding information from dna.

Chromatin

Is a complex of macromolecules found in cells, consisting of DNA, protein and RNA.

Organelle

Is any discrete macromolecular structure in the cytoplasm specialized for a particular function.

Endomembrane system

Is composed of the different membranes that are suspended in the cytoplasm within a eukaryotic cell. These membranes divide the cell into functional and structural compartments, or organelles.

Primary walls

Laid down when the cell is still growing.

Central vacuole

Large, membrane-bounded sac. It is often the largest organelle in the cell. functions to hold materials and wastes.

Endoplasmic reticulum (ER)

Largest internal membrane.

Chromosomes

Located inside the nucleus of animal and plant cells. made of protein and a single molecule of deoxyribonucleic acid (DNA).

Actin filaments

Long fibers about 7cm long.

Nucleoid

(meaning nucleus-like) is an irregularly-shaped region within the cell of a prokaryote that contains all or most of the genetic material, called genophore.

Amyloplast

A leucoplast that stores starch(amylose) is sometimes termed .

Thylakoids

A membrane-bound compartment inside chloroplasts and cyanobacteria.

Cell wall

A rigid layer of polysaccharides lying outside the plasma membrane of the cells of plants, fungi, and bacteria. In the algae and higher plants, it consists mainly of cellulose.

Cytoplasm

A semifluid matrix that fills the interior of the cell.

Centriole

A small set of microtones arranged in a specific way. 9 groups

Adherens junctions

Anchoring junctions, connect the actin filaments of one cell with those of neighboring cells or with the extracellular matrix.

Stroma

Animal tissue

Ribosomal(RNA)

Are ribosome composed of two subunits.

Vacuoles

Are specialized membrane-bounded structures found in plant cells.

Grana

Are stacked membranes in closed compartments of chloroplasts .

Ribosomes

Are the protein builders or the protein synthesizers of the cell. Ribosomes are special because they are found in both prokaryotes and eukaryotes.

Prokaryotes

Are the simplest organisms. cells are small, and consist of cytoplasm surrounded by a plasma membrane and are encased withing a rigid cell wall. very important in ecology of living organisms. Do not contain organelles characteristic.

Mitochondria

Are typically tubular or sausage-shaped organelles about the size of bacteria that are found in all types of eukaryotic cells .

Chloroplasts and mitochondria have many common features because both

Arose by endosymbiosis.

Surface area-to-volume ratio

As a cell get larger, its volume increases at a faster rate than its surface area. if the cell radius increases by 10 times, the surface area increases by 100 times, but the volume increases by 1000 times. A cell's surface area must be large enough to meet the metabolic needs of its volume.

Middle lamella

Between the walls of adjacent cells a sticky substance.

Desmosomes

Cell structure specialized for cell to cell adhesion

Plasma membrane

Encloses a cell and separates its contents from its surroundings.

Eukaryotic cells are more complex than prokaryotic cells. Which of the following are found only in a eukaryotic cell?

Endoplasmic reticulum.

Integrins

Fibronectin molecules bind not only to ECM glycoproteins but also to proteins.

Golgi body

Flattened stacks of membranes, often interconnected with one another, forming a complex.

Peroxisome

Important type of microbody.

Cisternal space or lumen

Inner region of the ER.

The cytoskeleton includes?

Intermediate filaments made of twisted fibers of vimentin and kertatin.

Anchoring junctions

Mechanically attach the cytoskeleton of a cell to the cytoskeletons of other cells or to the extracellular.

Lysosomes

Membrane-bounded digestive vesicles.

Cytoskeleton

Where all eukaryotic cells are supported by an internal protein scaffold.

Differences between bacteria and archaea?

The molecular architecture of their cell walls.

Secondary walls

The secondary cell wall is a structure found in many plant cells, located between the primary cell wall and the plasma membrane.

The smooth endoplasmic reticulum is?

The site of lipid and membrane synthesis.

Nuclear envelope

The surface of the nucleus that is bonded by two phospholipid bilayer membranes.

Partitioning the sheet

The tight junctions between the cells lining the digestive tract also partition the plasma membranes of these cells into seperate compartments.

Eukaryotic cells are composed of three types of cytoskeletal filaments. How are these three filaments similar?

They contribute to the shape of the cells.

Plasmodesmata in plants and gap junctions in animals are functionally similar in that?

They form channels between cells that allow diffusion of small molecules.

Different motor proteins like kinesin and myosin are similar in that they can?

Use energy from ATP to produce movement.

Flagella

Whip like structure that allows a cell to move ex Bacteria, archaea

Eukaryote

DNA found in nucleus

Cadherins

Proteins.

All eukaryotic cells posses each of the following except?

Cell walls.

Chloroplasts

Chloroplasts are the food producers of the cell. Chloroplasts work to convert light energy of the Sun into sugars that can be used by cells.

Matrix

Compartment in the cristae partition the mitochondrion. lying inside the membrane;

Gap junctions

Composed of structures called connexons, complexes of six identical transmembrane proteins.

Tight junctions

Connect the plasma membranes of adjacent cells in a sheet.

Plasmodesmata

Cytoplasmic connections that form across the touching plasma membranes.

Transmission electron

Electrons used to visualize the specimen are transmitted through the materials

Cristae

Mitochondria are bonded by two membranes: a smooth outer membrane, and an inner folded membrane with numerous contiguous layers.

Cisternae

Newly formed or altered glycoproteins and glycolipids collect at the ends of the Golgi bodies in flattened, stacked mambrane folds.

Glycoproteins

Newly synthesized proteins can be modified by the addition of short-chain carbohydrates.

Light microscope

Operates with visible light, use two magnifying lenses to achieve high magnification and clarity

Plastids

Organelles-chloroplast,leucoplasts,and amyloplasts.

Intermembrane space

Outer compatment in the cristae mitochondrion.

Cytosol

Part of the cytoplasm that contains organic molecules and ions in solution.

Tonoplast

The membrane surrounding vacuole.

Basal body

The microtubulules of the flagellum .

Resolution

The minimum distance two points can be apart and still be distinguished as two separate points

Peptidoglycan

Polymer consisting of sugars and amino acids that form mesh like layer outside the plasm membrane of bacteria forming the cell wall

The protein sorting pathway involves the following organelles/compartments in order:

RER, transport vesicle, Golgi, final destination.

Smooth ER (SER)

Regions of the ER with relatively few bound ribosomes.

Rough ER

Rough ER (RER) is involved in some protein production, protein folding, quality control and despatch.

Nuclear pores

Shallow depressions in the electron micrographs.

Cilia

Slender, microscopic, hair like structures or organelles that extend from the surface of nearly all mammalian cells

Vesicles

Smaller sacs that store and transport a variety of materials.

The most important factor that limits the size of a cell is the?

Surface area-to-volume ratio of the cell.

Pericentriolar material

Surronding the centrioles in the centrosome.

Golgi apparatus

The Golgi body

Creating sheets of cells

The cells that line an animal's digestive tract are organized in a sheet only one cell thick.

Nucleolus

The dark-staining zone many nuclei exhibit.

Nucleus

The largest and most easily seen organelle withing a eukaryotic cell.

Microtubules

The largest of the cytoskeletal elements, are hollow tubes about 25nm in diameter.composed of a ring of 13 protein prorofilaments.