Sapling Exam 1

Which statements describes examples of facilitated diffusion?

- A kidney cell absorbs water molecules down their concentration gradient using a membrane protein - A neutron allows a potassium ions to leave the cell down their concentration gradient using a membrane channel - An inner ear hair cell allows chloride ions to flow down their concentration gradient after a molecule binds to a membrane receptor.

DNA Facts

- A single molecule that can b ever 10000000 nucleotides long - The genome for eukaryotic organisms - Double stranded - Base thymine

RNA Facts

- A single molecule that can form a complex secondary structure - Single stranded - Translated into a protein - Includes ribose sugar

Descriptions of sodium-potassium pump

- Adenosine triphosphate (ATP) is necessary for the pump's function - The pumps helps a maintain the contraption of sodium and potassium ions in living cells

Peripheral membrane

- Attact at the cell membrane surface

Integral membrane

- Extend through the cell membrane - Move laterally (sideways) in the hydrophilic - Pump substances across the cell membrane

Cell/Virus

- Genetic material capable of undergoing evolution by natural evolution

Virus

- Genetic material protected by protein coat -Depend on a host to replicate

Key features of genetic material

- It must be variable through infrequent mutation - It must be able to store and express information - It must be able to replicate and transmit to progeny

Purines and pyrimidines in DNA molecules

- Purines consist of a two ring structure - Purines form hydrogen bonds with pyrimidines

Cells

- Respond to environment - Contain organelles - Biological processes

Which statements are properties of protein-facilitated active transport?

- The cells spends energy to move substances through a protein across the plasma membrane - Substances move from an are of lower concentration to an area of higher concentration

What is a peptide bond ?

A covalent bond formed when the carboxyl group of one molecule reacts with an amino group of a different molecule

Ribozyme is ...

An RNA catalyst

Examples of lipid

Cell membrane Hormones Bee-wax

Carbohydrate complex

Cellulose Glycogen Starch

Transport

Cytochromes are electron carriers in the electron transport chains

Carbohydrate simple

Glucose Lactose Sucrose

Which molecule are the main structural components of the plasma membrane?

Proteins Lipids

The structure of DNA

- The two anti-parallels sugar-phosphate backbones twist to form a double helix - Adenine is paired with thymine, and guanine is paired with cytosine - The five-carbon sugar of DNA is called deoxyribose

Which statements describe hydrogen bonding between water molecules or describe properties of water that lead to hydrogen bonding between water molecules?

1. A water molecule is polar because it has a bent structure and its shared electrons are more attracted to the oxygen atom than hydrogen atoms 2. The slightly negative oxygen atom of one water molecule is attracted to the slightly positive hydrogen atom of another water molecule

Which statements are true regarding the cell membrane's role in homeostasis?

1. If there is an excess of carbon dioxide molecules permeate the membrane and leave the cell 2. Passive forms of transport move molecules such as water across the cell membrane with no energy added

Statements of Nonpolar Bonds

1. The bond between hydrogen atoms in diatomic hydrogen H2 2. Electrons of adjoined atoms are equally distributed between those atoms.

Statements of Polar Bonds

1. The bond between oxygen and hydrogen in water H20 2. Electrons are not equally shared by the atoms in a covalent bond 3. One atom has a partial negative charge and the other atom has a partial positive charge

A few unidentified seeds were found in a sealed clay jar during an archaeological dig. Radiocarbon dating showed that the seeds were 725 years old. When the seeds were planted, plants brewed from them. Based on cell theory, what statements can confidently be made regarding these unidentified plants and seeds

1. The cells in the seeds are still alive, so they produced new plant cells. 2. Both the seeds and mature plants are composed of cells.

Water has ...

A high specific heat which means it takes a lot of energy to change its temperature

Which statement describes the fluid mosaic model?

A phospholipid bilayer with various molecules embedded within the floating between the layers

Structural

Actin proteins are part of a cell's cytoskeleton and help maintain cell's shape

Which is not a tenet of cell theory?

All cells contain DNA genome

Cell theory began to develop in 1839, following the research of Matthias Schleiden and Theodor Schwann into plant and animal tissues. Both the botanist Schleiden and the physiologist noticed that every organism they viewed under a microscope, whether plant or animal, was composed of cells. Their observations that all living species are made up of one or more cells led to early formation of cell theory. Which tenet of cell theory is described by the paragraph about the historical observations of cells?

All organisms are composed of one or more cells.

What are the monomers, or building blocks of a protein?

Amino acids

Immunity

Antibodies recognize specific pathogens in the body

Molecular formula of carbohydrate

C3H6C3

Move easily through the lipid bilayer of the plasma membrane

Carbon dioxide

Using X-ray crystallography, Rosalind Franklin was able to produce X-ray diffraction images of DNA that were clearer than any previously produced images What did the images show regarding the structure of DNA?

DNA molecules are in the shape of a double helix

A liver cell synthesizes glycogen from glucose

Energy storage

The tertiary structure of a protein is the:

Folded 3-dimensional conformation of a single polypeptide chain

Which is a highly branched polysaccharides molecule in animals? It is stored in muscles and is used to provide energy in muscle cells.

Glycogen

Cell membranes are composed of phospholipids that have head and tail regions. The phospholipid tail is hydrophobic and spontaneously orients to the inside the membrane. Which of the phrases best describes the hydrophobic portion of a phospholipids?

Has few interactions with water

What intermolecular force is responsible for holding the two strands of a DNA double helix together?

Hydrogen bond

Which statements about covalent bonds is true?

In a nonpolar covalent bond, the electrons are shared equally between 2 atoms.

Cell membranes are composed of phospholipids that have head and tail regions. The phospholipid head is hydrophilic and spontaneously oriented toward the environment. Which of the phrases best describes the hydrophilic region of a phospholipid?

Interacts with water

Both DNA / RNA

Made of nucleotides Contains codes for proteins

A heart cell uses the energy in glucose to synthesize ATP

Metabolism for energy

Signaling

Mitogen-activated protein (MAP) kinases direct a cell's response to stimuli, such as heat shock

Carbohydrate polymers are composed of:

Monosaccharides joined by glycosidic bonds

Bulk Transport

Movement of contents of transport vesicles into the cells by endocytosis

Active Transport

Movement of solutes into the cell against their concentration gradient using membrane proteins

Simple diffusion

Movement of solutes into the cell directly through the plasma membrane

Facilitated diffusion

Movement of solutes into the cell down their concentration gradient using membrane proteins

Which statements about hydrogen bonds is true?

Oxygen and nitrogen can participate in hydrogen bonding because they are more electronegative than hydrogen

Facilitated diffusion is a protein0facilitated movement of solutes across a membrane from an area of higher concentration to an area of lower concentration. Which terms best describes facilitated diffusion?

Passive transport

The mechanisms of bacteriophage

Phage replication requires the cellular machinery of the host bacteria for biosynthesis

Metabolism

Pyruvate kinase is a glycolysis enzyme that plays a role in breaking down glucose

Butter, which is a solid at room temperature is often used in cooking

Saturated

Coconut oil, which is a solid at room temperature can be used as an alternative to butter

Saturated

Need help from a protein to cross the membrane because they are repelled by the lipid bilayer

Sodium chloride Potassium ion Amino acids Fructose

A plant cell synthesizes cellulose from glucose

Structural support

A DNA molecule consists of two polynucleotide strands that form a double helix. The strands are held together by hydrogen bonds between the nitrogen - containing bases. One strand is complementary to the other strands, which means that a base on one strand is paired with a base on the opposite strand. The nucleotide bases in DNA are adenine (A), cytosine (C), guanine (G) and thymine (T) What DNA sequence is complementary to AGTC

TCAG

What characteristics is common to all living organism, but is not a characteristic of viruses?

The capability of autonousmly carrying out biological processes

Which statements about teaching intelligent design in a science classroom is correct?

There is no specific evidence to support intelligent design and therefore it should not be taught in a science class

How did Hershey and Chase determine that DNA contained genetic information?

They labeled virus DNA and proteins with different radioactive isotopes and saw that only DNA was present in cells when the viruses infected the cells

What contribution did James Watson and Francis Crick make to our understanding of DNA?

They modeled the structure of DNA based on limited data available

Olive oil, which is liquid at room temperature is used in cooking pasta

Unsaturated

The oil inside flaxseed oil pills is liquid at room temperature

Unsaturated

DNA only

Uses thymine Double stranded

RNA only

Uses uracil Single stranded

Viruses rely on host cell to carry out metabolic functions. What molecule does a virus insert into a host cell that enable the virus to redirect the host cell's enzymes and ribosomes?

Viral DNA or RNA

How does high specific heat capacity of water help to regulate body temperature?

Water can be used to cool the body through evaporating cooling Water can absorb a large amount of heat before changing temperature

Water accounts for 60% to 90% of the mass of every cell, and it dissolves many substances that are used or produced in cellular chemical reactions. Although it does not dissolve all substances, water is sometimes called the universal solvent. Which property of water contributes to its ability to dissolve most molecules in the cell?

Water has polar bonds and is a polar molecule

What type of molecule is water and why?

Water is a polar molecule because oxygen and hydrogen have different electronegativities