Unit 2 - Cell Structure and Function

Intermediate filaments

________ constructed from a class of proteins called keratins; are thought to function as reinforcement for the shape and position of organelles in the cell.

Giardia

________- example of diplomonad- an infectious agent that takes hold in the intestines and denies the body the ability to absorb any fat.

Adenosine triphosphate

________ (ATP)- called on to provide the energy.

Bound

________ ribosomes- attached to endoplasmic reticula and form proteins that tend to be exported from the cell or sent to the membrane.

Osmoregulation

________- the ability to maintain water balance; allows organisms to control their internal environments by maintaining the right concentrations of solutes and the amount of water in their body fluids.

Binary fission

________- process where duplication of genetic material, division into half and production of two identical daughter cells occurs.

Vacuole

________- storage organelle that acts as a vault.

Lysosome

________- membrane- bound organelle that specializes in digestion.

host organelles

Are the ________ for the Krebs cycle (matrix) and oxidative phosphorylation (cristae) of respiration.

Isotonic

________ indicates there is no net movement of water across the membrane.

external signals

Proteins on the exterior of a membrane with binding sites can act as receptors that allow the cell to respond to ________ such as hormones.

Matrix

________- the innermost portion of the mitochondrion.

Mitochondria

________- the power plants of the cell.

vesicle

A(n) ________- escorts the substance to the plasma membrane, causes it to fuse with the membrane, and ejects the contents of the substance outside the cell; functions as the trash chute of the cell.

SER

Liver cells- contain a lot of smooth endoplasmic reticulum (________) as they host a lot of carbohydrate metabolism (glycolysis)

hypotonic solution

As water enters the cell from a(n) ________, pressure is applied to the plasma membrane until the cell ruptures.

protein

A(n) ________ that stretches across the membrane can function as a channel to assist the passage of desired molecules into the cell.

Ribosomes

________- Function as the host organelle for protein synthesis in the cell.

Osmosis

________ would drive water from the region with 10 particles of sodium toward the region with 15 particles of sodium.

Peroxisomes

________- organelles containing enzymes that produce hydrogen peroxide as a by- product while performing various functions, like breakdown of fatty acids and detoxification of alcohol in the liver.

endoplasmic reticulum

Rough ________- membrane- bound organelle; termed "rough "because of the presence of ribosomes on the cytoplasmic surface of the cell.

Cytoskeleton

________- The skeleton of cells consists of three types of fibers that provide support, shape, and mobility to cells: microtubules, microfilaments, and intermediate filaments.

Water

________ enters the cell due to osmotic pressure from the higher solute concentration in the cell.

Fluid mosaic

________ model the most accepted model for the arrangement of membranes.

Cristae

________- the folds created by the inner of the two membranes*

Archezoa

________- the eukaryotic organism that scientists believe most closely resembles prokaryotes; does not have mitochondria.

basic unit of life

Cell- ________, discovered in the 17th century by Robert Hooke.

Chloroplast

________- site of photosynthesis and energy production in plant cells.

Microtubules

________ constructed from tubulin, have a lead role in the separation of cells during cell division; are also important components of cilia and flagella, which are structures that aid the movement of particles.

Plasma

________ membrane- selective barrier around a cell composed of a double layer of phospholipids.

Nucleus

________- Control center of the cell.

Stroma

________- inner fluid portion,**** surrounded by two outer membranes.

muscular contraction

Microfilaments, constructed from actin, play a big part in ________.

Plant cells

________ maintain a positive pressure to hold their shape, allowing them to stay rigid.

Eukaryotic ribosomes

________- built in a structure called the nucleolus.

Eg

________: the cells of the tail of a tadpole are digested as a tadpole changes into a frog.

Free

________ ribosomes- exist freely in the cytoplasm and produce proteins that remain in the cytoplasm of the cell.

ER

Called smooth ________ because there are no ribosomes on its cytoplasmic surface.

efficiency of materials

As the surface- area- to- volume ratio of a cell increases, the exchange ________ with the environment increases as well.

internal volume

As a cell grows in size, its ________ increases, and its cell membrane (surface area) expands to respond to the growth of the cell.

hypertonic solution

In a(n) ________, water moves out of the cell, causing the cell to shrivel.

Factors of selectivity

________- the size of the substance, the charge.

Osmotic pressure

________ is measured as the force needed to stop osmosis.

eukaryotic cells

In ________, this is the storage site of genetic material (DNA)

Cell

________ membrane- selective barrier surrounding a(n) ________; has a phospholipid bilayer as its major structural component.

potassium pump

Sodium- ________ actively moves potassium into the cell and sodium out of the cell against their respective concentration gradients to maintain appropriate levels inside the cell.

SER

The liver also contains ________ as it is the site of alcohol detoxification.

endoplasmic reticulum

Smooth ________- membrane bound organelle involved in lipid synthesis, detoxification, and carbohydrate metabolism.

Eg

________: cells have a very high concentration of potassium and a very low concentration of sodium.

Mitochondria

________- double- membraned organelles that specialize in the production of ATP.