unit #3

cell theory

The idea that all living organisms are composed of cells, and all cells come from preexisting cells are the two major tenets of __________   __________.

Robert Hooke

The person credited with discovering the cell is __________     __________

eukaryotic

The type of cell that contains a true nucleus and is found in animals, plants, fungi, protozoa, and algae is __________.

prokaryotic

Bacteria and archaea are both __________ cells.

nucleus & organelles

Eukaryotic cells have a true ______ and complex _______ that specialize in performing certain metabolic functions.

nucleoid

Instead of a nucleus, prokaryotic cells have an irregularly-shaped area containing the cell’s genetic material known as a __________.

Which cell type is generally larger? 

eukaryotic

phospholipid bilayer

The plasma membrane of a cell is composed of a __________     __________.

cytosol

Cellular fluid is referred to as __________ and is mostly water and dissolved ions.

nuclear envelope

The nucleus is surrounded by the __________     __________.

nucleolus

The dense, rough spherical body within the nucleus is called the __________ and is the site of ribosome manufacture in eukaryotic cells.

chromatin

Giant particles of tightly wound spools of DNA found in the nucleus is called __________.

euchromatin

less tightly packed and easily available for transcription

heterochromatin

more tightly packed and contains DNA the cell does not use.

DNA

The most important function of the nucleus is to store the cell's __________.

false

All cells contain one and only one nucleus.

endoplasmic reticulum

The __________     __________ is the folded, convoluted network of lipid bilayer membranes that course throughout the cytoplasm.

proteins

The rough endoplasmic reticulum manufactures __________ in a lipid-friendly environment.

post office

The Golgi apparatus is like the __________     __________ of the cell – it stores, modifies, packages, and ships proteins in membranous sacs called vesicles.

proteins & amino

Ribosomes manufacture _______ from building blocks called _____ acids.

mitochondrion

The organelle that produces the majority of a cell's energy is the __________.

endosymbiosis

Evolutionary biologists theorize that mitochondria were once separate prokaryotic organisms that were incorporated into eukaryotic cells – a process known as __________.

chloroplasts & chlorophyll

_____ are membrane-enclosed sacs that contain the green pigment _____, responsible for the process of photosynthesis.

vacuoles

Vesicles designed for storage that can contain water, food particles, etc. are known as __________.

cytoskeleton

The protein framework that forms a scaffold helping to give shape and support to a cell, as well as perform locomotion, is known as the __________.

cilia & flagella

____ & ____ are hair-like or whip-like structures composed of microtubules that aid cells in locomotion.

lipids

Membranes are primarily composed of __________.

selectively permeable

Membranes provide a __________  __________barrier, where some materials are able to be transported into and out of the cell.

phospholipids, glycolipids, & cholesterol

The three most common lipid molecules in membranes are

phospholipids

The most abundant molecules in membranes are

amphipathic or amphiphilic

These molecules are termed _______ or ______ because they contain a region that likes water, and a region that likes lipids.

hydrophilic

means "water-loving" and describes polar molecules that interact well with water.

hydrophobic

means "water-fearing" and describes non-polar molecules that do not interact with water, but interact well with lipid molecules. 

a phospholid bilayer

Biological membranes are best described as which of the following?

cholesterol

The molecule that can modulate the fluidity of membranes and also serves as a starting molecule for synthesis of steroid hormones is __________.

integral

Proteins that are embedded in the membrane are termed

peripheral

Proteins attached to the surface of the membrane are termed

Enzymes

Many functions. Serve as catalysts that aid reactions.

Receptors

Bind chemical messengers

Channel Proteins

selectively allows ions and molecules through the membrane — e.g. sodium

Carrier Proteins

Carries hormones or other molecules through the membrane — e.g. insulin is carried into cells

glycolipids & glycoproteins

The two types of carbohydrate molecules found in membranes are

carbohydrate

__________ groups usually serve as identity markers and recognition sites, allowing the cell to be identified as well as identify other cells or foreign substances.

lipids

The most abundant molecules in biological membranes are:

passive & active

In general terms, there are two types of transport:

diffusion

__________ is the movement of matter or energy down a concentration gradient, from an area of high concentration to an area of low concentration until an equilibrium is reached.

simple & facilitated

The two types of diffusion across a cell membrane are

simple diffusion

__________  __________ occurs passively, unaided, and spontaneously (i.e. it will occur by itself without any external influence or the input of energy).

Ions

Which of the following substances would NOT be able to cross a plasma membrane by the process of simple diffusion?

channel & carrier

There are two types of facilitated diffusion:

osmosis

__________ is the process whereby solvent molecules (typically water) will move through a semipermeable membrane into an area of higher concentration of solute.

osmotic pressure

The pull of solute on water molecules is termed __________  __________.

isotonic

A cell placed in a(n) __________ solution will maintain its normal shape because the amount of water entering the cell is equal to the amount of water leaving the cell. 

hypotonic

A cell placed in a ________ solution will swell and burst (undergo hemolysis)

hypertonic

A cell placed in a _________ solution will shrink and shrivel (undergo crenation). 

low & high

Active transport moves ions or molecules up their concentration gradients - from areas of _____ concentration to areas of _____ concentration.

energy & ATP

Active transport requires the use of ____, , usually in the form of ____.

It uses ATP to expel 3 sodium ions from the cell and import 2 potassium ions

Which option is true regarding the sodium-potassium pump?