GES 103 Test #1
Carbohydrates
- Sugars: main energy source for cells -composed oc ch2o(n) -Basic Unit - Polysaccharide
Organic Chemicals- Biological Macromolecules
-Carbohydrate -Proteins -Liquids -Nucleic Acids
Neutral Atoms
-Equal number of protons and electrons
Steroids
-Four fused carbon rings *cholesterol and sex hormones *maintain fluidity of membranes in animal cells
Chemical Bonds
-Help to stabilize structures -Iconic bond: electrons are transferred between + and - -Covalent bonds: electrons shared between two atoms
Water Facilitates Chemical Reactions
-Promotes contact between solutes
Atoms
-Smallest units that consist of -Protons (+) -Neutrons -Electrons (-)
Inorganic Chemicals
-Water -Acids -Bases -Salts
Hydrogen Bonds
-Weak Attraction between negative h+ and partially negative adjacent atom
What Statistical Tests Cannot Tell Us
-Whether there is observer bias -Whether the experiment was designed appropriately -Whether the experiment was carried out correctly
Proteins perform what functions as macromolecules?
-forms integral part of cell membrane -regulates chemical reactions, -forms channels in the cell membrane, and acts as hormones
Lipids
-hydrophobic molecules composed of hydrogen & carbon -Three types *Fats *steroids *phospholipids
Proteins
-important structural components of cells -Basic unit: amino acid
Approximately what proportion of the carbon dioxide currently being introduced into the atmosphere is as a result of the cutting and burning of forests in the tropics?
25%
The population of the United States is about ___________ of the total world population but is responsible for about ____________ of the global fossil fuel production.
4%; 25%
Polymers of amino acids form a polypeptide. What is the shape of a polypeptide?
A folded or coiled string of beads
What are the products of light reaction?
ATP, NADPH, & Oxygen as a by product.
What does the term complementary mean when it is applied to DNA?
Adenine always pairs with thymine; cytosine always pairs with guanine
Which of the following molecules provides the energy that maintains concentration gradients across cell membranes?
Adenosine triphosphate
Professor A.N. Shent studies carbon dioxide. Dr. Shent describes her trip last year to the Arctic to retrieve and analyze fossil air. Your classmates are laughing at her, but you have studied and know that she is talking about which of the following?
Air compressed and trapped in deep ice sheets.
What are essential amino acids?
Amino acids the body can not synthesize
Which of the following is a true statement regarding antioxidants?
Antioxidants inhibit the effects of free radicals.
Why is it impossible to prove a scientific hypothesis completely true?
Because of the existence of alternate hypothesis
The main wavelengths of light that are absorbed by the chlorophyll in plants include those that are shorter, which appear ___________ to our eyes, and those that are longer, which appear ___________ to our eyes.
Blue / Red
Which of the following do cellular respiration and photosynthesis have in common?
Both use an electron transport chain to generate ATP
Plants that use C4 photosynthesis are better adapted to hot, dry conditions than C3 plants. One possible way to keep the rate of photosynthesis constant in the face of global warming, then, would be to replace C3 plants with C4 plants. Why is this unlikely to have the desired effect?
C4 plants are grasses, whereas c3 plants are trees; grasses remove substantially less carbon dioxide from the atmosphere than trees.
Which of the following is true in prokaryotes but not in eukaryotes
Cell Wall
Chemical reactions
Changes in chemical composition of substances
Photosynthesis begins when light energy is harvested from the sun by plants. What is the initial electron donor in photosynthesis?
Chlorophyll
The green light-absorbing pigment in leaves is called _____________ and is located ______________, which are disk-like membranes.
Chlorophyll; on the thylakoid membranes.
Which of the listed organelles consists of a series of membranous sacs and contains pigment molecules?
Chloroplasts
Epidemiologist often gain information form which of the following types of study?
Correlational
Which of the following is not located in the cytoplasm of eukaryotic cells?
DNA
Which of the following is the single biggest contribution an individual can make to decreasing his or her own carbon dioxide production?
Drive an energy efficient vehicle
At what point in photosynthesis is oxygen released?
During the light reactions
Practical Significance
Even statistically significant results may not have real world practical effects
Which of the following substances uses facilitated diffusion to cross the cell membrane?
Glucose
A six-carbon glucose molecule and its components pass through which of the listed stages, and in which order, in the process of cellular respiration?
Glycolysis, citric acid cycle, and electron transport chain
Aerobic cellular respiration occurs in four stages. What is Stage 1 called, and what is its product that enters into Stage 2?
Glycolysis; pyruvic acid
Which of the following is a benefit of the greenhouse effect?
Helps keep Earth's temperature compatible with life.
Which of the following is a correct pairing between the commercial process that adds hydrogen atoms to unsaturated fats and one of its products?
Hydrogen and margarine
Which choice shows the substances that rely on facilitated diffusion to cross the cell membrane?
Hydrophilic molecules & charged molecules
Which of the following pathway is correct for the Calvin cycle?
It begins when rubisco catalyzes the reaction between RuBP and carbon dioxide, and ends with the production of sugar.
Which of the following is an accurate statement about roughage in the diet?
It consists of complex carbohydrates and Provides bulk to feces.
How is photosynthesis affected by high temperatures?
It is reduced because plants close their stomata and less carbon dioxide is taken in.
Some molecules, such as glucose, require proteins for transport across the cell membrane. This method does not require energy. Why is this form of transport a type of diffusion?
It relies on a concentration gradients
You are studying the metabolism of a species of jade plant. You discover that it appears to open its stomata only at night. Your careful research also shows that the Calvin cycle operates in this plant only during daytime. Which of the following statements about this jade plant is most likely true?
It uses CAM photosynthesis and stores carbon dioxide as an organic acid.
A polyunsaturated fat contains which of the following?
Many double bonds between carbon atoms
Which of the listed substances does not contain carbon?
Minerals
Which of the following best describes the process of facilitated diffusion across a cell membrane?
Movement of a solute down its concentration gradient with the help of membrane proteins
Dr. Santos believes that aloe vera cream helps heal wounds; after all, her family has used it for generations. She conducts a study of this effect on patients who visit her dermatology practice. Which type of bias could likely occur, and what kind of placebo-controlled study should she design to avoid it?
Observer Bias; Double blind
____ are to cells as organs are to the body.
Organelles
Anaerobic respiration takes place in the absence of ___________ and leads to the buildup of __________ in the body.
Oxygen, lactic acid
Name the gas that is used in place of carbon dioxide during photorespiration, and name one product of this process.
Oxygen; glycolate
Name the gas that is used in place of carbon dioxide during photorespiration, and name one product of this process?
Oxygen; sugar
Which of the following concentrated energy sources are types of fossil fuels?
Petroleum, coal, & natural gas.
A chain of many sugar monomers is joined by chemical bonds forms a?
Polysaccharide
Which of the following choices lists the major macromolecules found in living things?
Proteins, Carbohydrates, lipids, & nucleic acids
units of a sugar, phosphate, and a nitrogen-containing base make up which of the following molecules?
RNA, DNA
Photosynthesis occurs when light energy excites chlorophyll and becomes chemical energy. This powers the most important reaction on Earth. Which of these are the two reactants and the two products of photosynthesis?
Reactants: carbon dioxide and water; Products: glucose and oxygen.
Which of the following is correct pairing of an organelle and its function ?
Ribosome and protein assembly
What is the important structural difference between rough endoplasmic reticulum (ER) and smooth ER?
Rough Er has a lipid membrane; smooth does not
Reactants
Solutes that are changed
What is the source of the oxygen that is produced in photosynthesis, and at what point in the process is it produced?
Splitting of water molecules; light reactions.
Which of the following occurs when fossil fuels are burned?
Stored carbon is released into the atmosphere as carbon dioxide.
The thick fluid within the chloroplast is called the ___________, which is the location of ___________.
Stroma; the Calvin Cycle
The electron transport chain ends with the movement of H+ ions (protons) across the inner mitochondrial membrane. What is the result of this movement?
Synthesis of ATP from ADP and phosphate
Ice core data from Antarctica show that the level of carbon dioxide in the atmosphere is higher today than at any other time in the last 400,000 years. Which of the following has increased and decreased at about the same times as (in parallel with) carbon dioxide levels over the same time period
Temperature
You are swimming in a fish-filled lake whose water temperature is about 60 degrees. Which contains more heat, the lake or your body? why?
The lake; the total amount of molecular movement in the lake's volume is greater than in your body
Water is a good solvent because of its hydrogen bonds. Which of the following statements is true of this type of bond?
They can be intramolecular or intermolecular
Which of the hollowing statements is true regarding DNA nucleotides in DNA?
They form antiparallel strands connected by hydrogen bonds
By which of the following measure can it be said that bacteria are more successful organisms than humans?
They have adapted to more, and more, diverse environments.
What role do vitamins play in the body?
They serve as coenzymes to speed up chemical reactions.
What makes up the plasma membrane
Two layers of phospholipids
Molecule
Two or more atoms held together by chemical bonds
Ions
Unequal number of protons and electrons
Which of the following are included in the term greenhouse gases?
Water vapor, carbon dioxide and methane.
We eat to gain macronutrients. What substances are included in the term macronutrients?
Water, carbohydrates, fats, and protein
Organic molecules are molecules that contain _______, which can form bonds with as many as ____ other elements
carbon, 4
Carbohydrate and protein molecules both contain ________, however, protein molecules also contain_____ in addition
carbon, hydrogen and oxygen; nitrogen
what is found in animal cells but not in plant cells
centrioles
Table sugar, or sucrose, is a _______ consisting of ______________
disaccharide; fructose & glucose
An ____ is made of atoms, the smallest units that have the properties of that ____ . When atoms form covalent bonds, a ____ is formed
element, element, molecule
Substance R is too large to diffuse across the cell membrane or to be transported across by a protein. Molecules of Substance R can, however, cross the membrane and exit the cell. By which of the listed processes do they cross?
exocytosis
Fats
glycerol and three fatty acid tails Fats store energy
water has a stronger resistance to temperature change than most other substances. This property of water can be attributed to its __________.
hydrogen bonds
In the phospholipid bilayer of the plasma membrane, the heads of the phospholipids are ____ and face ____
hydrophilic; outward
What is the driving force in evolution?
natural selection
When placed in solutions with different concentrations of salt, animal cells may change their shape. Which of these processes determines whether the cells expand, shrink, or remain the same shape?
osmosis
Table salt easily dissolves in water. This occurs because of which of the following properties of water?
polarity
Statistical significance
probability of less than 5% due to chance alone
Products
result of the chemical reaction
The induced fit model of enzyme catalysis states that _____________.
the active site of the enzyme changes shape after substrate binds to it
