Bio Ch 3
A shortage of phosphorus in the soil would make it especially difficult for a plant to manufacture __________.
DNA
Hydrocarbons are organic molecules that contain only ______
carbon and hydrogen atoms
Which of the following formulas represents a nucleotide?
C10H14N5O7P. The only building block that contains a phosphorous (P) is a nucleotide.
Which of the following are differences between DNA and RNA? DNA uses A, T, C, G; RNA uses A, U, C, G DNA is double stranded; RNA is single stranded Hydrogen bonds only form in DNA molecules. The 5-carbon sugar in DNA is deoxyribose; the sugar in RNA is ribose sugar.
DNA uses A, T, C, G; RNA uses A, U, C, G DNA is double stranded; RNA is single stranded The 5-carbon sugar in DNA is deoxyribose; the sugar in RNA is ribose sugar.
How do prions disrupt the normal function of an organism and cause diseases such as mad cow disease?
Prions can convert normally folded proteins into abnormal shapes. A protein's function depends on its normally folded shape. Mad cow disease, kuru, and chronic wasting disease are three examples in which prions cause disease by altering a protein's normally folded shape. The abnormally folded protein molecules clump together and disrupt brain function.
The building blocks of proteins are called _______
amino acids
Which of the following functions are carried out by proteins? Select all that apply. catalysis (enzymes) transport regulation defense (antibodies) store information
catalysis (enzymes) transport regulation defense (antibodies)
Which level is most important in determining the structure and function of a protein?
primary. The order in which amino acids are found in the protein (primary structure) ultimately determines how the protein folds and, thus, how it functions.
Which of the following formulas represents a triglyceride?
C55H98O6 Lipids consist of an abundance of C and H, along with a few bridging O. There is no nitrogen or phosphorous
Which of the following formulas represents a carbohydrate?
C8H16O8. Simple sugars exist in a 1:2:1 C:H:O ratio
The large diversity of biological molecules depends on atoms of the element __________. This element can make stable bonds to itself and to atoms of other elements. Without this element, the large macromolecules that make up most of the molecules in living organisms would not be possible.
Carbon. With four electrons that can be shared to make covalent bonds, carbon-based molecules display an enormous variety of sizes, shapes, and properties.
One difference between DNA and RNA is that __________.
DNA uses the bases CGAT, whereas RNA uses the bases CGAU. In RNA, uracil is substituted for thymine.
The addition of __________ groups to carbon-based molecules provides many unique properties of biologically important molecules.
Functional
Why is carbon considered the building block of life?
It can form four covalent bonds. Its four unpaired valence electrons allows carbon to form four covalent bonds. This allows carbon-based molecules to take a variety of shapes.
All lipids share this characteristic.
Lipids don't dissolve in water. Lipids are hydrophobic, which means they do not dissolve in water.
Which two statements are true about dehydration synthesis? Monomers or polymers are joined to form longer chains. Polymers are broken down into shorter chains or monomers. A molecule of water is consumed. Its atoms are added to a bond, putting an OH group on one end and a hydrogen atom on the other. An OH group from one component and an H atom from the other form a water molecule.
Monomers or polymers are joined to form longer chains. An OH group from one component and an H atom from the other form a water molecule.
With which nucleotide does adenine base-pair in a DNA molecule?
T. The DNA base-pairs are A-T and G-C. When RNA folds into a complex structure, the pairs are A-U and G-C.
Even though lactose intolerance is found in only about 10% of current northern Europeans, researchers studying 7,000-year-old fossil remains of ancient European populations found that most were lactose intolerant. What conclusion might you draw from this evidence?
The mutation for lactose tolerance can arise spontaneously in any population. In Europe, this mutation has rapidly become prevalent through natural selection only within the past 7,000 years.
Through examining DNA from lactose-intolerant individuals, scientists found that __________.
a small change in a DNA nucleotide sequence can have a major effect on the production of lactase
Which of the following are functions of RNA? Select all that apply. permanent, pristine copy of the genetic material in cells aids in multiple aspects of protein synthesis regulates translation important part of cell membranes
aids in multiple aspects of protein synthesis regulates translation
What is the name of the building block of complex proteins?
amino acid. Amino acids are the building blocks of proteins. They can either be non-essential (made by the cells of our body) or essential (required from our diet).
Plant cell walls consist mainly of _________
cellulose. The polysaccharide called cellulose is a major component of the tough walls that enclose plant cells.
"Saturated" fats __________.
contain only single bonds in their fatty acid tails. Saturated fats are called "saturated" because they have the most possible hydrogen atoms in their fatty acid components. In unsaturated fats, there are fewer hydrogen atoms because carbon atoms linked by double bonds have fewer attached hydrogen atoms than carbons linked by single bonds.
What is the term used to describe the unfolding of a protein?
denaturation. The breaking of the weak bonds that keep a protein folded is due to extreme environmental conditions like extreme temperature and pH. The loss of structure results in a loss of function. This is why high fevers are so dangerous to humans, as proteins start to unfold.
What type of carbohydrate is lactose?
disaccharide. Two sugar rings covalently bonded together makes a disaccharide (di- = two). This bond in lactose is broken by the digestive enzyme lactase. Those that are lactose intolerant are unable to digest this disaccharide. As a result, the bacterium in the colon digest the sugar, producing gases like methane and sulfur gas. This causes the bloating and smelly flatulence associated with lactose intolerance.
All organic molecules contain carbon and hydrogen. What parts of an organic molecule may contain oxygen, nitrogen, or phosphorus?
functional groups. Functional groups are the parts of biological molecules that often participate in chemical reactions. Different functional groups may contain oxygen, nitrogen, phosphorus, or other elements.
A specific stretch of DNA that codes for the amino acid sequence of a polypeptide is called a __________.
gene
Which of these are monomers? glucose protein lactose amino acid cellulose
glucose, amino acid. Amino acids form protein polymers. Glucose forms various polymers, including starch and cellulose
What is the main sugar used by cells for energy?
glucose. Cells use glucose for energy in the process of cell respiration.
Graphs to study
https://photos.app.goo.gl/hQ9tJKf8pfbYc2qk7
An important characteristic of the double-stranded DNA molecule is that __________.
hydrogen bonding between base pairs is responsible for formation of a double helix. Although individual bonds are weak, collectively they form a very stable double helix.
Which of the following lipids is an important component of the outer membrane of certain bacteria called Gram-negative bacteria?
lipopolysaccharide. Lipopolysaccharide (LPS) is released when a bacterial cell dies. This causes an immune response in the human host that results in inflammation, dangerously low blood pressure, and fever. In some cases at high levels, LPS can cause death.
The building blocks of nucleic acid molecules are called ________
nucleotides. Nucleotides are the building blocks for the nucleic acids: RNA and DNA.
A polypeptide is a long chain of amino acids bonded together by _______
peptide bonds. Peptide bonds form between the amino group of one amino acid and the carboxyl group of another.
What is the name of the covalent bond that holds two adjacent amino acids together?
peptide. Peptide bonds are formed by dehydration reactions
Which level of protein structure is characterized by twists and turns stabilized by hydrogen bonds?
secondary. Twists called alpha-helicies and folds called beta-sheets are held together by hydrogen bonds. These localized structures allow the peptide chain to start to take more compact structures.
Glucose plus fructose forms a disaccharide called _________
sucrose. glucose and fructose form sucrose
Globally, most human adults are lactose intolerant. People with lactose intolerance produce insufficient amounts of _______
the enzyme lactase. Lactase breaks down lactose to simpler sugars that can be digested
Carbohydrates are used as raw materials to assist in the construction of important cellular structures. Which of the following bacterial structures are rich in carbohydrates? Select all that apply: the glycocalyx the flagellum the bacterial cell wall the nuclear envelop
the glycocalyx, the bacterial cell wall
When researchers studied lactose intolerance in people from different geographic regions, they concluded that ________
there may be a selective advantage that favors lactose tolerance in populations that depend on dairy products as a staple in their diet
A dehydration reaction is the process in which __________.
water molecules are formed when polymers are synthesized from monomers. In a dehydration reaction, monomers are connected to each other to create polymers. Water is released as a by-product with each monomer addition.
