BISC 207: 4.3, 4,4. 4.5, 4.6, 10.1, 10.2

Genome

The entire complement of an organism's or species' genetic material passed between cells and generations.

Genes

Segments of DNA within the genome containing information to produce thousands of different proteins.

Prokaryotic cells

Simple cells that lack a membrane-enclosed nucleus, comprising bacteria and archaea.

Plasma membrane

A phospholipid bilayer with embedded proteins forming a barrier between the cell interior and exterior.

cytoplasm

A jellylike fluid inside the cell in which the organelles are suspended

Nucleoid

The non-membrane-bound region in the cytoplasm of prokaryotes where genetic material is located.

ribosomes

involved in polypeptide synthesis-found in the cytoplasm

Ribosomal proteins and RNA then enter the nucleolus and are assembled into ribosomal subunits which exist the nucleolus and move through the nuclear pores into the cytosol where the carry of polypeptide synthesis

Cell wall (Prokaryotes)

A relatively porous structure containing peptides and carbohydrates that supports and protects prokaryotic cells.

Glycocalyx

An outer viscous covering surrounding bacteria that traps water and prevents drying out.

Capsule

A gelatinous glycocalyx that helps bacteria avoid destruction by immune systems or aid in surface attachment.

Pili

Projections that allow prokaryotic cells to attach to surfaces and to each other.

Flagella (Prokaryotes)

Appendages that provide prokaryotic cells with the ability to move (motility).

eukaryotes

organisms made up of one or more cells that have a nucleus and membrane-bound organelles

cell compartmentalization

possess a true nucleus

organelle

A compartment, usually bounded by one or more membranes, with its own unique structure and function

Compartmentalization

The presence of membrane-bound organelles in eukaryotes that allows specialized chemical reactions in different regions.

Liquid-liquid phase separation

A compartmentalization mechanism where aggregated solutes form spherical droplets with measurable surface tension and viscosity.

--Molecules can diffuse within the droplet and occasionally leave it and pass into the surrounding liquid phase

Cytosol

The region of a eukaryotic cell outside the organelles but inside the plasma membrane.

metabolism

All of the chemical reactions that occur within an organism

--involves the metabolic pathways which is catalyzed by a specific membrane

enzyme

a protein that accelerates the rate of a chemical reaction

chromatin

Clusters of DNA, RNA, and proteins in the nucleus of a cell

plasma membrane

A selectively permeable phospholipid bilayer forms the boundary of the cells

controls the movement of substances into and out of the cell; site of cell signaling

mitochondria

An organelle found in large numbers in most cells, in which the biochemical processes of respiration and energy production occur--site of ATP synthesis

Centrosome

A structure present in the cytoplasm of animal cells that functions as a microtubule-organizing center and is important during cell division. A centrosome has two centrioles.

Catabolism

The breakdown of molecules into smaller components to utilize energy and generate metabolic building blocks.

Anabolism

The synthesis of molecules and macromolecules in cellular metabolism.

cytoskeleton

A network of fibers that holds the cell together, helps the cell to keep its shape, and aids in movement

microtubules, intermediate filaments, and actin filaments

Each type of protein filaments are constructed from many protein monomers

Microtubules

Hollow tubulin tubules aiding in cell shape, organelle organization, chromosome sorting, and intracellular movement.

dynamic instability

The rapid switching between growth and shrinkage shown by microtubules.

microtubule organizing center

a site in a eukaryotic cell from which microtubules grow

Intermediate filaments

Twisted protein filaments (e.g., keratin, lamin) providing mechanical strength and nuclear anchorage.

Tension-bearing fibers that help maintain cell shape and rigidity

Lengths are permanent

Actin filaments (Microfilaments)

Spiral actin strands supporting cell shape, strength, muscle contraction, and cytokinesis.

Plus and minus ends

Central role in the formation and function of pseudopodia

pseudopodia

A cellular extension of amoeboid cells from the plasma membrane used in moving and feeding.

Facilitate amoeboid movement-motility exhibited by cells such as amoebas, white blood cells, and some cancer cells

Motor proteins

Proteins utilizing ATP hydrolysis to promote cargo transport, filament movement, or bending.

Consists of a head, hinge and tail

Hinge and tail make up a structure called the lever arm

Head is the site where ATP binds and is hydrolyzed to adenosine diphosphate (ADP) and inorganic phosphate

flagella

whiplike tails found in one-celled organisms to aid in cellular movement or the movement of extracellular fluid

Cilia

Hairlike projections that extend from the plasma membrane and are used for locomotion--shorter and more numerous than flagella

cilia and flagella

Cause movement by generating bends that move along their length and push backward against the surrounding fluid

Axoneme

The internal structure of eukaryotic cilia and flagella containing a 9+2 microtubule array and dynein.

basal bodies

centrioles forming the bases of cilia and flagella--anchored to the cytoplasmic side of the plasma membrane

the microtubules here form a triplet structure, provides a site for microtubules to grow

Nuclear envelope

A double membrane structure that encloses the eukaryotic nucleus.

Nucleolus

A droplet organelle in the nucleus responsible for assembling ribosomal subunits.

endomembrane system

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

Nuclear pores

Passageways formed by the nuclear membrane that regulate molecular transport into and out of the nucleus.

chromosomes

found in each nucleus-composed of genetic material, namely DNA, and many types of proteins that help to compact the chromosome to fit inside the nucleus

Chromatin

the complex formed between DNA and proteins that makes up eukaryotic chromosomes

nuclear matrix

consists of the nuclear lamina and an internal nuclear matrix which is connected to the lamina and fills the interior of the nucleus

chromosome territory

A distinct area where each chromosome is located within the cell nucleus of eukaryotic cells; chromosome territories do not overlap.

Rough Endoplasmic Reticulum

ER studded with ribosomes involved in protein sorting, insertion, and glycosylation.

membrane vesicles

where proteins are packaged into-small spheres enclosed by a membrane-move from one location in the endomembrane system to another

Smooth Endoplasmic Reticulum

ER lacking ribosomes, functioning in lipid synthesis and modification, detoxification, and calcium ion storage-contains calcium pumps to transport calcium ions into the ER lumen-involved in muscle contraction

Golgi apparatus

A stack of flattened membranes (cisternae) involved in processing, protein sorting, and secretion.

secretory vesicles

A membrane vesicle carrying different types of materials that fuses with the cell's plasma membrane to release the contents extracellularly-golgi packages different materials into these

secretory pathway

Rough ER -> Golgi -> secretory vesicles -> plasma membrane -> cell exterior

Lysosomes

Small animal organelles containing acid hydrolases (break down covalent bonds with water) to break down macromolecules.

Contain many different types of acid hydrolases that allow them to break down various complex material

vacuoles

prominent organelles in plant, fungal, and other protist cells-function is varied-sturcture and degradation (break down food), removes excess water

Central vacuole

A prominent plant organelle providing storage, regulation of cell volume, and turgor pressure- helps to drive expansion of cell wall and maintain structure.

Peroxisomes

Organelles containing catalase that break down hydrogen peroxide and metabolize fats and amino acids.

Play a role in the metabolism of fats and amino acids-glyoxysomes

membrane transport

the movement of ions or molecules across the membrane-involves plasma membrane proteins-functon to transport essential nutrients or ions into the cell and involved in the export of substances

cell signaling

A vital function of the plasma membrane in which cells to sense changes in their environment and communicate with each other.

cell adhesion

A vital function of the cell membrane that allows cells to bind to each other-critical in the formation of multicellular organisms and provides a way to convey positional information between neighboring cells.

Mitochondrion

A semiautonomous organelle with cristae that converts chemical energy (glucose) into ATP to be readily used by cells.

Involved in synthesis, modification, and breakdown of several types of cellular molecules

intermembrane space

mitochondria--highly invaginated (folded) to form projections called cristae

cristae

Infoldings of the inner membrane of a mitochondrion that houses the electon transport chain and the enzyme catalyzing the synthesis of ATP.

increase the surface area of the inner membrane of the mitochondria,

Chloroplasts

Semiautonomous plant organelles containing thylakoid membranes that capture light energy to synthesize organic molecules via photosynthesis.

photosynthesis

Conversion of light energy from the sun into chemical energy.

thylakoid membrane

A membrane within the chloroplast that forms many flattened, fluid-filled tubules that enclose a single, convoluted compartment.

The membrane contains chlorophyll and is the site where the light-dependent reactions of photosynthesis occurs.

granum and stroma

granum

a structure composed of stacked membrane-bound thylakoids within a chloroplast

stroma

the compartment of the chloroplast that is enclosed by the inner membrane but outside the thylakoid membrane

Endosymbiosis theory

The proposal that mitochondria and chloroplasts originated from a symbiotic relationship involving early eukaryotic cells.

Extracellular matrix (ECM)

A complex meshwork of secreted material outside animal cells that provides strength, support, and signaling.

Collagen

An animal protein secreted to form large fibers that impart high tensile strength to the ECM.

Elastin

A protein forming elastic fibers in the ECM with remarkable elastic properties.

Form covalent crosslinks to make a fiber

Proteins go from compact to linear

cellulose

macromolecule of the plant cell wall-polysaccharide made of repeating molecules of glucose attached end to end-provide great tensile strength

primary cell wall

In plants, a relatively thin and flexible layer first secreted by a young cell.

secondary cell wall

In plant cells, a strong and durable matrix that is often deposited in several laminated layers around the plasma membrane and provides protection and support.

--more variable than primary

cell junctions

specialized structures that adhere cells to each other or to the ECM.

Anchoring junctions

Cell junctions (like adherens junctions and desmosomes) that mechanically hold adjacent cells together or to the ECM.

Tight junctions

Intercellular junctions made of transmembrane proteins that seal cells together and prevent leakage.

Gap junctions

A cluster of channels allowing direct exchange of ions and small molecules between adjacent cell cytosols.

Cadherins and Integrins

Cell adhesion molecules (CAMs) mediating cell-to-cell junctions (cadherins) or cell-to-ECM connections (integrins).