bio test 6
Life's key molecule for storing energy for for powering work at the cellular level is a nucleotide called
ATP
What property of dishwashing liquid (detergent) makes it useful to wash grease from pans?
Amphipathic nature
If you were a molecule, then facilitated diffusion would be most like
Coasting across a bridge on your bike.
Which of the following best describes what occurs during facilitated diffusion?
In facilitated diffusion, molecules diffuse into the cell through protein channels. No cell energy is required.
Which of the following particles could diffuse easily through a cell membrane?
Oxygen (O2)
Molecules which diffuse through a cell membrane by facilitated diffusion
Require the aid of transport proteins
Which of the following best describes how phospholipids arrange themselves in the cell membrane?
The phospholipids form a bilayer where the hydrophilic heads face outward toward the watery exterior or the watery cytoplasm, and the hydrophobic tails cluster together in a water-free zone.
Because they're found in living things, the molecules in living things are often called
biomoleules
A type of mitochondria-rich fat tissue called ________ fat is used for regulating body temperature in babies and in hibernating mammals
brown
In a peanut butter and jelly sandwich, both the bread and the jelly would be classified as
carbohydrates
Sugars, starches, and plant fiber are all
carbohydrates
Passive transport is defined as the movement of any substance across a membrane without the use of
cell energy
The boundary that surrounds the cytoplasm of the cell is the ______ ______________
cell membrane
The polysaccharide that makes up plant fiber is called
cellulose
Wood and cotton are both made of the polysaccharide called
cellulose
The dynamic model of cell membrane structure which involves phospholipids, proteins, cholesterol, and carbohydrates in constant motion in the membrane is the _______-_______ model.
fluid-mosaic
The phosphate containing part makes up the phospholipid's "_________".
head
The nucleic acids DNA and RNA are the molecules of
heredity
The kind of bond that lipids won't form with water is a ___________ bond
hydrogen
Is the head of a phospholipid hydrophobic or hydrophilic?
hydrophilic
A more scientific way to say "water-loving" is __________.
hydrophillic
A more scientific way to say "water-fearing" is __________.
hydrophobic
Is the tail of a phospholipid hydrophobic or hydrophilic?
hydrophobic
Lipids are all ____________, which means that they won't dissolve in water.
hydrophobic
Lipids are all _____________, which means that they won't dissolve in water.
hydrophobic
A gummy bear is placed in water. The gummy bear is made mostly of sugar, held together by gelatin. The gummy bear is ___________ to the water.
hypertonic
A solution that has a higher solute concentration than a solution on the other side of the membrane is ___________
hypertonic
A solution that has a lower water concentration than a solution on the other side of the membrane is ___________
hypertonic
When a plant is in this environment, it wilts.
hypertonic
When animal cells are in this environment, they'll shrink and shrivel
hypertonic
A solution that has a higher water concentration than a solution on the other side of the membrane is ___________
hypotonic
A solution that has a lower solute concentration than a solution on the other side of the membrane is ___________
hypotonic
When animal cells are in this environment, they'll expand, then burst.
hypotonic
When plant cells are in this environment, they'll be the most solid and firm.
hypotonic
In addition to energy storage, the fatty blubber found in marine mammals provides them with a layer of _________________ to protect them from heat loss
insulation
Marine mammals like whales use fat for
insulation
A solution that has the same solute concentration as a solution on the other side of the membrane is ___________
isotonic
A solution that has the same water concentration as a solution on the other side of the membrane is ___________
isotonic
If you want to keep animal tissue or cells alive outside the body, you have to keep them in what kind of osmotic environment?
isotonic
Fats, oils, waxes, and steroids are members of the _________ family
lipid
Fats, oils, waxes, and steroids are all examples of
lipids
The kind of endocytosis in which the membrane only pinches in when a molecule outside the cell binds with a receptor molecule in the membrane is called ____________.
receptor-meditated endocytosis
Membranes allow certain molecules to pass through but not others. In other words, membranes are ________-_______________.
selectively-permeable
The cell membrane lets only some things in and out. The best way to describe that is to say that the membrane is
semi-permeable
Another terms for "monosaccharide" is __________ sugar
simple
When substances diffuse directly through a membrane's phospholipid bilayer, the process is called _____________ ____________.
simple diffusion
Saturated fats are usually ________ at room temperature
solid
The polysaccharide found in bread, pasta, and rice is called
starch
Both testosterone and estrogen are hormones that belong to a class of lipids called
steroids
Both monosaccharides like glucose and disaccharides like sucrose are
sugars
The two fatty acid chains make up the phospholipid's "_________".
tail
A chemical name for both fats and oils is
triglyceride
True or false? Osmosis is a type of diffusion.
true
Cellulose makes up the cell _________ of plants
wall
Muscle tissue, skin, fingernails, enzymes, and antibodies are all examples of __________.
proteins
When a substance created inside the cell is exported outside the cell, it leaves the cell through
exocytosis
When substances diffuse into a cell by passing through a protein channel, the process is called _____________ ____________.
facilitated diffusion
True or false: In active transport, a cell uses the kinetic energy in molecules and lets them flow down their concentration gradient.
false
Triglycerides have ___ fatty acids bonded to one molecule of glycerol.
3
For diffusion to occur, there must be
a gradient
In nerve cells, the amount of positively charged potassium ions inside the cell is much higher than the amount outside the cell. In order for the cell to take up more potassium, which process is required?
active transport
When cells expend energy to move a substance from lower concentration to higher concentration, this process is known as _____________ ____________.
active transport
Which of the following terms describes the process by which the cell membrane moves substances from lower concentration to higher concentration.
active transport
Diffusion is a term for the movement of molecules from
an area of high concentration to an area of low concentration.
One way to talk about diffusion is to say the molecules in a fluid will move down a _____________ ____________.
concentration gradient
When a cube of sugar is placed in a beaker of water, sugar molecules spread through the beaker by
diffusion
_____________ is the movement of molecules from where they're more concentrated to where they're less concentrated.
diffusion
Sucrose, also known as table sugar, is formed by linking together two monosaccharides. That makes it a
disaccharide
When molecules diffuse, they flow
down their concentration gradient
The cell membrane pinches in, taking in something outside of the cell and enclosing it within a vesicle. This process is called ____________.
endocytosis
Fats and oils have more ___________ /gram than any other type of food.
energy
One of the key functions of fat and oil is their ability to store lots of ____________
energy
The fondness for sugar shared by many animals (including humans) evolved because sugars are a quick source of
energy
A vesicle filled with some substance fuses with the membrane, releasing that substance outside the cell. This process is called ____________.
exocytosis
Unsaturated triglycerides are usually _________ at room temperature
liquid
Because they're often big, the molecules in living things are often called
macromolecules
Diffusion is about the random movement of
molecules
Biomolecules are often composed of smaller building blocks, which are also known as
monomers
___________ get combined with one another to form polymers
monomers
The monomers of carbohydrates are
monosaccharides
The protein-based tissue that makes it possible for you to move (and which is what you eat when you eat chicken or beef) is
muscle
Suppose a cell has the following molecules and structures: enzymes, DNA, ribosomes, plasma membrane, and mitochondria. It could be a cell from ________.
nearly any eukaryotic organism
A molecule that can diffuse freely through a phospholipid bilayer is probably
non polar
Is the tail of a phospholipid polar or non-polar?
non-polar
One thing that the lipids have in common is that they are, for the most part, ____________, which is why they generally won't dissolve in ____________
non-polar; water
DNA and RNA are both examples of
nucleic acids
The molecules of heredity, DNA and RNA, are
nucleic acids
Antibodies and enzymes are both
proteins
Cell membrane channels are made of
proteins
The kind of endocytosis in which a large portion of the membrane surrounds a food particle (or even another cell), and then brings that particle into the cell is called _________
phagocytosis
As part of the immune response, a white blood cell swallows an invading bacteria. Another name for that process is
phagocytosis.
The molecules that make up that basic structure of the membrane are called __________.
phospholipids
Which of the following molecules makes up the basic structure of the membrane?
phospholipids
The kind of endocytosis in which a small portion of the membrane pinches in, allowing the cell to "take a sip" of the fluid outside of the cell, is called _________
pinocytosis
In most lipids (and in most parts of lipid molecules), electrons are shared evenly among the atoms that make up the molecule. As a result, lipid molecules are non- ________
polar
Is the head of a phospholipid polar or non-polar?
polar
The repeating glucose subunits in starch make starch a
polymer
Letters are to monomers as words are to
polymers
Foods like chicken, beef, and egg white are all members of the __________ biomolecule family
protein