Biology Ch. 4-6 (Exam 2)
trans site
close to the cell membrane
glycolysis
first step in releasing the energy of glucose, in which a molecule of glucose is broken into two molecules of pyruvic acid
cell wall
strong layer around the cell membrane in plants, algae, and some bacteria
activation energy
the energy that is needed to get a reaction started
H20
A biochemist wanted to study how various substances were used in cellular respiration. In one experiment, he allowed a mouse to breathe air containing O2 "labeled" by a particular isotope. IN the mouse, the labeled O2 first showed up in...
redox reaction
A chemical reaction involving the transfer of one or more electrons from one reactant to another; also called oxidation-reduction reaction.
entropy
A measure of disorder or randomness
feedback inhibition
A method of metabolic control in which the end product of a metabolic pathway acts as an inhibitor of an enzyme within that pathway.
endergonic reaction
A non-spontaneous chemical reaction in which free energy is absorbed from the surroundings.
become turgid... burst
A plant cell placed in distilled water will _____; an animal cell placed in distilled water will _______.
chemiosmosis
A process for synthesizing ATP using the energy of an electrochemical gradient and the ATP synthase enzyme.
selective permeability
A property of biological membranes that allows some substances to cross more easily than others.
electron transport chain
A sequence of electron carrier molecules (membrane proteins) that shuttle electrons during the redox reactions that release energy used to make ATP.
exergonic reaction
A spontaneous chemical reaction in which there is a net release of free energy.
rough ER... Golgi... transport vesicle... plasma membrane
A type of cell called a lymphocyte makes proteins that are exported from the cell. Which of the following traces the path of a protein from the site where its polypeptides are made to its export?
endergonic; exergonic; requires
ADP + Pi --> ATP is an _______ reaction, ATP ----> ADP + Pi is an ______ reaction, and the conversion of ADP + Pi to ATP ________ energy.
Acetyl CoA
After grooming the pyruvate molecule, what molecule is formed?
More cis-unsaturated and polysaturated fatty acids
An animal cell membrane will be more fluid at room temp. if it contains...
exocytosis
As a cell grows, its plasma membrane expands. Does this involve endocytosis or exocytosis?
oxaloacetate
At the end, citric acid cycle generates which molecule?
Some of it is stored in ATP; other is released as heat
Cellular respiration is an exergonic process. Remembering that energy must be conserved, what becomes of the energy extracted from food during cellular respiration?
lacks membrane bound nucleus, lacks membrane bound organelles, circular DNA, cell membrane/ cell wall, and has ribosomes
Characteristics of Prokaryotic cells
No
Does FADH2 form during glycolysis?
enzymes are usually made of proteins; some are made of RNA
Enzymes are made up of what kinds of molecules?
endosymbiotic hypothesis
Explanation of the origin of eukaryotic cells. Mitochondria and chloroplasts were one free living cells that became engulfed in another cell.
transport proteins... down
Facilitated diffusion across a membrane requires ____ and moves a solute _______ its concentration gradient.
membrane proteins
Floats within the membrane; proteins that function in transport, enzymatic activity, signal transduction, cell-cell recognition, intercellular joining, attachment to the cytoskeleton and extracellular matrix
reduction
Gain of electrons
breaks down into amino acids
How does a cell harvest energy from protein?
breaks down into glycerol and three fatty acids
How does a cell harvest the energy from fat?
the ribosomes are attached in the rough ER; rough ER has flat tubes and smooth ER has round tubes
How does the rough ER differ from the smooth ER?
Anaerobic: glycolysis and fermentation
How is energy harvested from glucose in the absence of oxygen?
2
How many ATPs are formed during fermentation?
2; 4
How many ATPs are used and how many ATPs are formed during glycolysis?
Glycolysis will decrease; the citric acid cycle will increase
How will excess acetyl CoA affect the rates of glycolysis and the citric acid cycle?
hydrolysis
Hydrolysis or dehydration synthesis breaks down ATP.
energy coupling
In cellular metabolism, the use of energy released from an exergonic reaction to drive an endergonic reaction.
oxidizes NADH to NAD+
In the absence of respiration (no oxidative phosphorylation), a cell can generate ATP by substrate-level phosphorylation in glycolysis if it:
synthesize ATP from ADP and Pi; increase oxygen consumption
Intact, isolated mitochondria are equilibrated to pH 8 in phosphate buffer, then transferred to phosphate buffer at pH 4 containing equal concentrations of ATP and ADP. These mitochondira will:
Lipid composition and temperature
Membrane fluidity is affected by...
tight junctions
Membranes of neighboring cells are pressed together, preventing leakage of extracellular fluid
surface proteins
Reside primarily on the inner or outer surface of the membrane; glycoproteins
ATP synthesis will decrease, oxygen consumption will stay the same
Some drugs known as uncouplers facilitate diffusion of protons across the mitochondrial inner membrane. When such a drug is added, what will happen to ATP synthesis and oxygen consumption?
is hypotonic to the protozoan
Some protozoans have special organelles called contractile vacuoles that continually eliminate excess water from the cell. The presence of these organelles tells you that the environment...
False
T or F. Cholesterol and long chain, saturated fatty acids make more fluid membrane.
False.
T or F. Most of the energy stored in ATP is present in the H-O bonds.
False
T or F. Plant cells perform photosynthesis, and animal cells perform cellular respiration.
True.
T or F. Short chain and unsaturated fatty acids are more fluid membrane.
contractile vacuole
The cell structure that collects extra water from the cytoplasm and then expels it from the cell
Small cells can better take up sufficient nutrients and oxygen to service their cell volume.
The cells of an ant and a horse are, on average, the same small size; a horse just has more of them. What is the main advantage of small cell size?
mitochondria
The cellular structure that is involved in producing ATP during aerobic respiration is the
lactic acid fermentation
The conversion of pyruvate to lactate with no release of carbon dioxide.
Singer and Nicholson
The fluid mosaic model was developed by...
receptor-mediated endocytosis
The movement of specific molecules into a cell by the inward budding of membranous vesicles containing proteins with receptor sites specific to the molecules being taken in; enables a cell to acquire bulk quantities of specific substances.
proteins embedded in a phospholipid bilayer
The plasma membrane consists principally of
First Law of Thermodynamics
The principle of conservation of energy. Energy can be transferred and transformed, but it cannot be created or destroyed.
endergonic reaction
The product of light by living organisms is referred as bioluminesence. It is an example of ________ reaction.
temp., size of molecule, and concentration gradient
The rate of diffusion depends on...
nucleoid
The region where the bacterial DNA occur...
active transport
The sodium concentration in a cell is 10 times less than the concentration in the surrounding fluid. How can the cell move sodium out of the cell?
stores energy in a form that can drive cellular work
The synthesis of ATP from ADP and Pi...
phosphorylation
The transfer of a phosphate group, usually from ATP, to a molecule. Nearly all cellular work depends on ATP energizing other molecules by phosphorylation.
transmission electron microscope
The ultrastructure of a chloroplast is best studied using a
True.
True or False. Bound ribosomes generally synthesize membrane proteins and secretory proteins.
True
True or False. Mitochondria are often more numerous near areas of major cellular activity.
False.
True or False. Prokaroytic and eukaryotic cells both have a cell wall.
protists, fungi, plants, and animals
Types of eukaryotic cells
All organisms are composed of one or more cells. The cell is the smallest unit having the properties of life.
What are Schleiden and Schwann proposed cell theories?
block the electron transport chain, block the gate of ATP synthase, and make the membrane of mitochondria leaky to H+
What are the 3 different categories of cellular poisons?
phospholipids, proteins, chloesterol, and sugar
What are the components of cell membrane?
1. branching 2. ester linkage/ ether linkage 3. L-glycerol/ D-glycerol
What are the differences between archaebacteria and bacteria membrane?
heat, light, electric current, mechanical energy, and radiation
What are the different forms of energy?
mitochondria and chloroplast
What are the energy related organelles in eukaryotic cells?
make proteins that are destined for secretion like insulin and milk
What are the functions of Rough ER?
synthesizes lipids, detoxifies toxic substances, and regulates muscle contractions by release of Ca+
What are the functions of Smooth ER?
structural support, recognition, catalyst, communication, transport
What are the functions of membrane proteins?
glucose, ATP, ADP, and NAD+
What are the inputs of glycolysis?
protection, structure, and transport
What are the major functions of cell membrane?
fat and protein
What are the other molecules by which a cell can harvest the energy?
1. Glycolysis 2. Citric acid cycle/ Kerbs cycle 3. Oxidative phosphorylation
What are the stages of cellular respiration?
chemical, mechanical, and transport
What are the three main types of cellular work?
1. yields 2 ATPs 2. yields 2 NADH 3. yield 2 Pyruvate
What are the three things glycolysis accomplishes?
yield 2 ATP, converts the carbon atoms into CO2, and transfers eight electrons to NADH and FADH2.
What are the three things the citric acid cycle accomplishes?
phagocytosis, pinocytosis, and receptor-mediated endocytosis
What are the three types of endocytosis?
kinetic and potential energy
What are the two states of energy?
transmission and scanning electron microscopes
What are the two types of electron microscopes?
alcoholic and lactic acid fermentation
What are the two types of fermentations?
exergonic and endergonic reactions
What are the two types of metabolic reactions?
transfer of phosphate and electrons
What are the two types of transferring energy in cells?
Inorganic and organic cofactors
What are two types of enzyme helpers?
competitive and noncompetitive inhibitors
What are two types of enzyme inhibitors?
nucleus and membrane bound organelles
What do eukaryotic cells have that prokarotic cells don't?
nuclear envelope, endoplasmic reticulum, golgi apparatus, and vesicles
What does the endomembrane system consists of?
lowers the activation energy
What does the enzyme do to the activation energy when it speeds up a chemical reaction?
All cells come only from other cells.
What is Virchow proposed cell theory?
basic unit of life
What is a cell?
It is a series of chemical reactions that involve energy changes
What is a metabolic reaction?
citrate and oxaloacetate
What is the beginning 6 carbon in the citric acid cycle? what is the end 4 carbon in the citric acid cycle?
Pyruvate
What is the end product of glycolysis?
water
What is the end product of oxidative phosphorylation?
It accepts electrons from the electron transport chain
What is the role of oxygen in cellular respiration?
It replenishes NAD+ so that glycolysis can produce ATP.
What is the value of the alcoholic fermentation pathway?
environmental factors (temp, pH, and light/dark), concentration of substrate, genes, phosphorylation, and enzyme inhibitors
What types of factors regulates the enzyme's activity?
water will move across the membrane by osmosis
When the concentration of solutes differs on the two sides of a membrane permeable only to water,
They run out of NAD+ and FAD
When the poison cyanide blocks the electron transport chain, glycolysis and the citric acid cycle soon grind to a halt as well. Why do they stop?
mitochondria matrix
Where does citric acid cycle occur in the cell?
electron transport system
Where does the oxidative phosphorylation occurs?
glycolysis; citric acid cycle and oxidative phosphorylation
Which of the three stages occurs in the cytoplasm? And which of the other two occur in the mitochondira?
1. light microscope 2. scanning electron microscope 3. transmission electron microscope
Which type of microscope would you use to study 1. the changes in shape of a living human white blood cell 2. the finest details of surface texture of a human hair 3. the detailed structure of an organelle in a liver cell?
Kidney cells must reabsorb a large amount of water when producing urine
Why are aquaporins important in kidney cells?
Because of hydrophobic tails and hydrophillic heads
Why can't the flipping of lipids occur across a bilayer?
The cell does not expend energy when it's going down it's concentration gradient.
Why is diffusion across a membrane called passive transport?
Yes
Yes or no. Is the movement of H+ across a membrane down its concentration gradient, the most immediate source of energy for making most of the ATP in cells?
endoplasmic reticulum
a cell structure that forms a maze of passageways in which proteins and other materials are carried from one part of the cell to another
concentration gradient
a difference in the concentration of a substance across a distance
Tay Sac disease
a disease caused by a malfunction of lysosomes
central vacuole
a membranous sac in a mature plant cell with diverse roles in reproduction, protection, growth, and development
compound microscope
a microscope that examines small or thinly sliced sections of an object
dissecting microscope
a microscope that studies an entire specimen in 3-D
micrograph
a photograph of the view through a light microscope
endomembrane system
a series of membrane that divides the inner cell's space into compartments where different cellular functions occur.
microfilament
about 7 nanometers in diameter, a solid rod of actin protein in the cytoplasm of almost all eukaryotic cells, making up part of the cytoskeleton and acting alone or with myosin to cause cell contraction
acetyl CoA
acetyl coenzyme A, a compound that is synthesized by cells and that plays a major role in metabolism
energy in biochemistry
capacity to change in the chemical composition and properties of molecule
lysosomes
cell organelle filled with enzymes needed to break down certain materials in the cell
cis site
close to the ER
chromatin
combination of DNA and protein molecules, in the form of long, thin fibers, making up the genetic material in the nucleus of a eukaryotic cell
gap junctions
communicating channels, provide cytoplasmic channels between adjacent cells
hypertonic
describes a solution whose solute concentration is higher than the solute concentration inside a cell
hypotonic
describes a solution whose solute concentration is lower than the solute concentration inside a cell
facilitated diffusion
diffusion of specific molecules across cell membranes through protein channels
osmosis
diffusion of water through a selectively permeable membrane
kinetic energy
energy of motion
potential energy
energy stored due to an object's position or arrangement
active transport
energy-requiring process that moves material across a cell membrane against a concentration difference
anchoring/ adhering function
fastening cells together into strong sheets
chlorophyll
green pigment in plants that absorbs light energy used to carry out photosynthesis
isotonic
having a solute concentration equal to that of another solution
Antoni van Leeuwenhoek
he improved lens on a microscope and was able to see more detail in his observations
microtubules
hollow tubes of protein about 25 nanometers in diameter, support the cell and moves organelles within the cell
citric acid cycle
in cellular respiration, series of chemical reactions that break down glucose and produce ATP; energizes electron carriers that pass the energized electrons on to the electron transport chain
ribosomes
located in the nucleus, cytoplasm and on the rough ER, make up RNA and proteins
oxidation
loss of electrons
peroxisomes
membranous sacs containing enzymes used to break down hydrogen peroxide, dispose of toxic substances and fatty acids
electron microscope
microscope that forms an image by focusing beams of electrons onto a specimen
cytoskeleton
network of protein filaments within some cells that helps the cell maintain its shape and is involved in many forms of cell movement
Robert Hooke
one of the first people to observe cells in a cork
chloroplast
organelle found in cells of plants and some other organisms that captures the energy from sunlight and converts it into chemical energy
golgi bodies
organelles that package cellular materials and transport them within the cell or out of the cell
cilia and flagella
part of cytoskeleton; consists of parts of microtubules arranged in a 9 + 2 arrangement, involved in a cells movement
chemical energy
potential energy in a substance that can be released by a chemical reaction
mitochondria
powerhouse of the cell, produces energy (ATP) from oxygen and sugar(Cellular respiration)
pinocytosis
process by which a cell takes in liquid from the surrounding environment
phagocytosis
process in which extensions of cytoplasm surround and engulf large particles and take them into the cell
enzymes
proteins that act as biological catalysts
deamination
removal of an amino group
metabolic pathway
set of chemical reactions through which an organism builds up or breaks down materials as it carries out its life processes
cell theory
states that all living things are composed of cells and that all cells come from other cells
alcoholic fermentation
the anaerobic process by which yeasts and bacteria break down sugars to form carbon dioxide and ethanol
energy
the capacity to do work
cellular respiration
the chemical energy stored in organic molecules is converted to a form that the cell can use to perform work
osmoregulation
the control of water balance
substrate
the molecule to which the enzyme attaches itself to
passive transport
the movement of substances across a cell membrane without the use of energy by the cell
endocytosis
the process by which a cell membrane surrounds a particle and encloses the particle in a vesicle to bring the particle into the cell
exocytosis
the process by which a substance is released from the cell through a vesicle that transports the substance to the cell surface and then fuses with the membrane to let the substance out
diffusion
the process by which molecules move from an area of higher concentration to an area of lower concentration
transmembrane proteins
the proteins of a membrane that span the entire membrane; integrins and junction proteins
active site
the site on an enzyme that attaches to a substrate
Thermodynamics
the study of energy transformations that occur in a collection of matter
product
the substances that form as a result of reaction
heat
thermal energy, is a type of kinetic energy associated with the random movement of atoms or molecules
noncompetitive inhibitors
these inhibitors bind to the enzyme somewhere else and change the shape of the enzyme
competitive inhibitors
these inhibitors compete with natural substrate for the enzyme's active site
plasma membrane
thin flexible barrier that regulates what enters and exits the cell; composed of two layers of lipids
nuclear membrane
thin structure that surrounds and protects the nucleus
chromosomes
threadlike structures made of DNA molecules that contain the genes
light microscope
uses visible light rays; specimens can be magnified up to 1,000 times their actual size
nucleus E.R. Golgi complex lysosome peroxisome mitochondria chloroplast
what are membrane bound organelles?
mitochondria matrix
where chemicals are transformed into ATP(energy) and where the ATP is stored, , chemical fluid filling the cristae, holds ribosomes, DNA, and enzymes
microscope resolution
Ability of a lens to separate or distinguish small objects that are close together.; shorter wavelength = greater resolution
scanning electron microscope
An electron microscope used to study the fine details of cell surfaces.
transmission electron microscope
An electron microscope used to study the internal structure of thin sections of cells
No, they have glyoxisomes.
Do plants have peroxisomes?
Second Law of Thermodynamics
Energy cannot be changed from one form to another without loss of usable energy.
2
How many ATPs are formed during citric acid cycle?
glucose... NAD+
In glycolysis, _____ is oxidized and ______ is reduced.
hypotonic solution
In what type of solution is a plant cell healthy in?
1. living material cannot be examined 2. very expensive 3. require much prep time 4. complicated to use
Limitations of electron microscope
extracellular matrix
Network of molecules outside of an animal cell membrane primarily composed of glycoproteins
plasmodesmata
Open channels in the cell wall of a plant through which strands of cytosol connect from an adjacent cell.
True
T or F. Citric acid cycle releases or captures more free energy than glycolysis.
False
T or F. Enzymes are chemically changed following the chemical reaction.
induced fit
The change in shape of the active site of an enzyme so that it binds more snugly to the substrate, induced by entry of the substrate.
bacteria and archaea
Types of prokaryotic cells
NADH, CO2, and Acetyl CoA
What molecules are formed during grooming of pyruvate molecule?
small
What size cell has a greater ratio of surface area to volume than a large cell of the same shape?
eukaryote
Which is a bigger cell eukaryote or prokaryote?
cytochromes proteins
Which protein serves as electron carriers in electron transport system?
lumen
a network of interconnected cavities and channels in the E.R.
nucleus
a part of the cell containing DNA and RNA and responsible for growth and reproduction
aquaporins
a transport protein in the plasma membrane of a plant or animal cell that specifically facilitates the diffusion of water across the membrane
tonicity
ability of a solution to cause a cell to gain or lose water
intermediate filament
about 10 nanometers in diameter, a component of the cytoskeleton that includes all filaments intermediate in size between microtubules and microfilaments.
ATP
adenosine triphosphate, an organic molecule that acts as the main energy source for cell processes; composed of a nitrogenous base, a sugar, and three phosphate groups
NAD+
an organic molecule that serves as an electron carrier by being oxidized and reduced to NADH
centrioles
animal only, involved in cell division, short cylinders with a 9 + 0 pattern of microtubule triplets
