Bio Chap 6

ribosome

tiny complexes made out of ribosomal RNA and proteins , are cellular components that carry out protein synthesis

light microscope (LM)`

visible light is passed through the specimen and then through glass lenses The lenses refract the light in such away the image of the specimen is magnified. Can look at living specimens

Magnification

the ratio of an object's image size to its real size

Resolution

clarity of image

Contrast

accentuates differences in parts of a sample

electron microscope (EM)

focuses a beam of electrons through the specimen or onto its surface

better resolution than light microscope but cant view living things without it dying

Ultrastructure

cellular anatomy revealed by an electron microscope

Scanning Electron Microscope (SEM)

is especially for detailed study of the surface of a specimen

Exterior

Transmission Electron Microscope (TEM)

is used to study the internal ultrastructure of cells interior

Cell Theory

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

Cytology

study of structure and function of cells

cell fractionation

takes cells apart and separates major organelles and other subcellular structures from one another

Ultracentrifuge

fractionate cells into their component parts by density

Cytosol

The semifluid portion of the cytoplasm.

Chromosomes

carry genes in forms of DNA,Protiens wrapped in DNA

Eukaryotic Cell

most of its DNA is found in the organelle called the nucleus, which is bounded by a double membrane

prokayotic cells

the DNA is concentrated in a region that is not enclosed called a nucleoid

Nucleoid

DNA is concentrated in a region not membrane enclosed

Cytoplasm

the region between the nucleus and the plasma membrane(eukaryote)

interior of a prokaryotic cell

plasma membrane

functions as a selective barrier that allows sufficient passage of oxygen, nutrients and wastes to service the entire cel

Nucleolus

Found inside the nucleus and produces ribosomes

Nucleus

contains most of the genes(DNA) in the eukaryotic cell and most conspicuous organelle

nuclear envelope

encloses the nucleus separating its contents from cytoplasm by a double membrane

pore complex

intricate proteins structure that regulates entry and exit of most proteins and RNA's in nucleus

nuclear lamina

net like array of protein filaments that maintain the structure of the nucleus by mechanically supporting the nuclear envelope

Chromomatin

material that makes up chromosomes , made out of complex proteins RNA and DNA in the nucleus of the cell(strings of DNA)

Free Ribosome

makes proteins for the cell in the cytoplasm

Bound ribosome

attached to rough ER, makes proteins for secretion out of the cell

Why are cells so small? Explain the relationship of surface area to volume.

Cells are small to maximize efficient material exchange and nutrient absorption, thanks to a high surface area-to-volume ratio. This ensures optimal functioning and waste removal while maintaining temperature regulation.

Vesicles

sacs made of membrane

Endoplasmic Reticulum(ER)

an extensive network of membranes that accounts for more than half of the endomembrane system in the eukaryotic cell

Smooth ER

Its outer surface lacks ribosomes, functions in diverse metabolism processes, synthesis of lipids, metabolism of carbohydrates, detoxication of drug or poison

Rough ER

Has ribosome on its outer surface, ribosomes on the ER secretes proteins(mostly glycoproteins) and distributes transports vesicles and also adds membrane proteins to grow plasma membranes

Glycoproteins

proteins that have carbohydrates covalently bonded to them help identify the cell

transport vesicles

Vesicles in transit from one part of the cell to another.

Golgi apparatus

A system of membranes that modifies proteins from the Rough ER packages them for export by the cell

cis(intake) trans(outake)

Golgi

modifies carbohydrate portions of glycoproteins and removes sugar monomers and substitutes others

lysosome

cell organelle filled with enzymes animals need to break down certain materials in the cell

Phagocytosis

a process in which amoebas and many other protists wat by engulfing smaller organisms or other food particles

Vacuole

membrane bounded vesicle whose functions vary in different kinds of cells

food vacuole

A membranous sac formed by phagocytosis of microorganisms or particles to be used as food by the cell.

contratile vacuole

pumps out excess water to maintain a suitable concentration of ions and molecules inside the cell

central vacuole

A membranous sac in a mature plant cell with diverse roles in reproduction, growth, and development.

tonoplast

a membrane which bounds the chief vacuole of a plant cell.

Mitochondria

are the sites of cellular respiration, the metabolic processes that generate ATP by extracting energy sugars fats and other fuels with help of oxygen

has its own DNA

(two membranes separating inner most place from cystol)

Chloroplast

found in plant and algae, are the sites of photosynthesis. They convert solar energy to chemicals energy by absorbing sunlight(makes ATP) and using it to drive the synthesis of organic compounds such as sugar from carbon

(three membranes separating innermost space from cystol)

Peroxisome

an oxidative organelle ,not part of the endomembrane. Can breakdown fatty acids then transport to mitochondria, detoxify alcohol and other drugs

converts hydrogen peroxide to water

Cristae

inner membrane of mitochondria, has infoldings creating high surface area, enhanced cellular respiration, divides mitochondria into two compartments

intermembrane space

the fluid filled space between the inner and outer mitochondrial membranes, usually has a lot of H+ ions

mitochondrial matrix

The compartment of the mitochondrion enclosed by the inner membrane and containing enzymes as well as mitochondrial DNA and ribosomes

Plastids

A group of membrane‐bound organelles commonly found in photosynthetic organisms and mainly responsible for the synthesis and storage of food.

Thylakoid

membranous system in the form of flattened interconnected sacs.

granum

A stack of thylakoids in a chloroplast

Stroma

fluid outside the thylakoids, contains chloroplast DNA, ribosomes as well as many enzymes

Cytoskeleton

a network of fibers extending through out of the cytoplasm, gives mechanical to the cell and maintains its shape

motor proteins

A protein that interacts with cytoskeleton, helps with cell mobility( encompasses both changes in cell location and more limited movements of the cell)

Microtubules

A hollow rod composed of two or more proteins which are globular proteins called tubulins that makes up part of the cytoskeleton in all eukaryotic cells and is found in cilia and flagella.

Helps carry vesicles around the cell

200nm to 250nm in length

endomembrane system

Cellular system that consists of the nuclear envelope, endoplasmic reticulum, Golgi apparatus,lysomes,vacoules,plasma membrane

Centrosome

A structure in animal cells containing centrioles from which the spindle fibers develop. microtubule organizing center

helps division of cells

centrioles

Centrioles are like the steering wheel of a cell, helping to organize cell division by forming a pair of structures made up of nine sets of microtubules in triplets arranged in a circular pattern.

Flagella

an undulating motion in the same direction as its axis

made of Microtubules

Cilia

works more like oars, with alternating power and recovery strokes generating force in a direction perpendicular to its axis, much as the oars of a crew boat, extend outward at right angles

made of Microtubules

basal body

a protein structure found at the base of a eukaryotic undulipodium (cilium or flagellum).

Micro filaments

solid rods about 7nm in diameter, are also called actin filament because they are built from molecules of actins, s

Actin

a globular protein

Cortex

the outer region of cytoplasm in a eukaryotic cell, lying just under the plasma membrane, more gel like consistency then inner regions, due to present of microfilaments

Myosin(thick)

thousand of actin filaments are arranged parallel to one another along the length of a muscle cell, interdigitated with thicker filament made of proteins act as motor proteins ,causes cell contraction

pseudopodia

In which a cell such as an amoeba crawls along a surface by extending and flowing into cellular extension

Caused by myosin and actin

cytoplasmic streaming

circular flow of cytoplasm within cells, common in large plants speeds up distribution of material

intermediate filaments

named for there diameter of 8nm-12nm large than microfilament but smaller than microtubules. Specialized for bearing tension

More permanent fixture cant be disassembled or reassembled, important for reinforcing the shape of the cell

cell wall

an extracellular structure of plant cells that distinguishes them from animal cells

FOUND IN PROKAYOTES

primary cell wall

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

middle lamella

The thin film between the cell walls of adjacent plant cells, rich in sticky polysaccharides called pectin.

seconday cell wall

added between the plasma membrane and the primary cell wall, in several laminated layers, has a strong and durable matrix to help cell protection and support

extracellular matrix

The substance in which animal tissue cells are embedded, consisting of protein(glycoproteins) and polysaccharides.

Collagen

structural protein found in the skin and connective tissue, makes strong fiber outside the cell

Proteoglycans

a glycoprotein consisting of a small core protein with many carbohydrate chains attached, found in the extracellular matrix of animal cells.

Fibronectin

An extracellular glycoprotein secreted by animal cells that helps them attach to the extracellular matrix.

Integrins

the principal receptors used by animal cells to bind to the extracellular matrix.

communication through integrins the extra cellular matrix can regulate cells behavior

Plasmodesmata

perforates cells wall with channels