BIO NO N MAJOR - EXAM 2

Which statement about an enzyme is TRUE?

An enzyme's function depends on its three-dimensional shape.

Part complete The sum total of all the chemical reactions that occur in organisms is called ________.

metabolism

The principle that energy cannot be created or destroyed is known as ________.

conservation of energy

Where in the cell does glycolysis occur?

cytoplasm

A process is referred to as aerobic if it requires ________.

oxygen

1 meter = ____ centimeters

100

Most human cells contain ______ chromosomes.

46 23 from each parent

Which of these provides the cell with structural support?

C Microfilaments are a component of the cytoskeleton.

___ is the self-replicating material present in nearly all living organisms; it is the main constituent of chromosomes and the carrier of genetic information.

DNA

Which of these is the double membrane that encloses the nucleus?

E This is the nuclear envelope.

Vacuoles are ______.

membranous sacs

___ is used in all steps of protein synthesis and carries the genetic information of many viruses.

RNA

What name is given to the process in which pre-mRNA is edited into mRNA?

RNA processing RNA processing edits the RNA transcript that has been assembled along a DNA template.

Chemical reactions that require oxygen are called __________, and those that do not require oxygen are called__________.

aerobic ... anaerobic Aerobic metabolism is much more efficient than anaerobic metabolism.

The nuclear envelope, endoplasmic reticulum, Golgi apparatus, lysosomes, and vacuoles make up the __________.

endomembrane system The endomembrane system partitions the cytoplasm.

Which of the following is a measure of randomness in a system?

entropy

What waste product do yeast produce under anaerobic conditions?

ethyl alcohol

Most of the ATP production during cellular respiration occurs __________.

from activity of the ATP synthase machine Electrons are removed from food molecules and carried by the electron transport chain to ATP synthase enzymes.

Substances that plug up an enzyme's active site are enzyme ________.

inhibitors

All of the following options (except one) are locations where ribosomes are found inside the cell. Choose the exception.

inside the nucleus

Lactic acid buildup in muscles is a sign that ________.

insufficient oxygen is reaching the muscles

An object at rest has no ________ energy, but it may have ________ energy resulting from its location or structure.

kinetic; potential

Which makes up portions of the cytoskeleton?

microtubules

Which of these are hollow rods that shape and support the cell?

microtubules Microtubules are rods that also play a role in organelle movement.

Electron transport takes place in the ______.

mitochondria

When electrons move through a series of electron acceptor molecules in cellular respiration ________.

oxygen is eventually reduced by the electrons in the formation of water

The _____ is a selective barrier, regulating the passage of material into and out of the cell.

plasma membrane The plasma membrane regulates the passage of material into and out of the cell.

A boulder at the top of a hill contains ________ energy.

potential

Diffusion ________.

proceeds until a dynamic equilibrium is reached

Photosynthetic organisms are ________.

producers that make their own organic matter from inorganic molecules

Respiration describes the exchange of gases between your blood and the air. Cellular respiration ________.

produces ATP

A product of glycolysis is ______.

pyruvic acid

An enzyme's function is most dependent on its ________.

shape

Similar to the nucleus, chloroplasts and mitochondria are ________.

surrounded by two membranes

In cellular respiration, most ATP is DIRECTLY produced as a result of ________.

the movement of hydrogen ions across the inner mitochondrial membrane

In eukaryotic cells the first step in protein synthesis is the _____.

transferring of information from DNA to messenger RNA Transcription is the first of the two main steps of protein synthesis.

Energy can be defined as ________.

the capacity to cause change

Osmosis can be defined as ________.

the diffusion of water across a selectively permeable membrane

The ultimate source of energy in food is ________.

the sun

What is the major function of chloroplasts?

to allow for photosynthesis to occur

What name is given to the process in which a strand of DNA is used as a template for the manufacture of a strand of pre-mRNA?

transcription Transcription is the process by which a DNA template is used for the manufacture of several different types of RNA.

What name is given to the process in which the information encoded in a strand of mRNA is used to construct a protein?

translation Translation is the process by which information encoded in RNA is used to manufacture a polypeptide.

Facilitated diffusion across a biological membrane requires ________ and moves a substance ________ its concentration gradient.

transport proteins; down

Photosynthetic organisms like grass are able to ________.

use molecules in the air as a major source of carbon

The waste products of cellular respiration include ________.

water and carbon dioxide

An animal cell placed in a hypertonic solution will __________.

lose water by osmosis and shrivel The hypertonic solution has a higher concentration of solutes. This causes water to diffuse out of the cell and shrivel.

Information is transferred from the nucleus to ribosomes via ______.

mRNA

RNA processing converts the RNA transcript into _____.

mRNA The editing of the RNA transcript produces mRNA.

Rough endoplasmic reticulum appears "rough" because __________.

many ribosomes stud the outside of the ER membrane These ribosomes are responsible for producing membrane proteins and secretory proteins.

Which of the following are the components of the cytoskeleton that help move chromosomes when cells divide?

microtubules Microtubules are straight, hollow tubes that attach to chromosomes and help move them during mitosis and meiosis.

Which is a function of the plasma membrane?

regulate traffic of chemicals in and out of the cell

If placed in tap water, an animal cell will undergo lysis, whereas a plant cell will not. What accounts for this difference?

relative inelasticity and strength of the plant cell wall

Anything that prevents ATP formation will most likely ________.

result in cell death

Which of these manufactures cellular membranes by adding membrane proteins and phospholipids to its own membrane?

rough endoplasmic reticulum As membrane proteins grow from ribosomes on rough ER, the proteins are embedded into the rough ER membrane.

Where is calcium stored?

smooth endoplasmic reticulum In addition to storing calcium, the smooth ER also plays a role in detoxification and lipid synthesis.

Plants use photosynthesis to ________.

store chemical energy, and they use cellular respiration to harvest energy from organic molecules

Which statement about enzymes is TRUE?

Enzymes catalyze specific reactions.

The endomembrane system includes ________.

Golgi apparatus, lysosomes, vacuoles, and the endoplasmic reticulum

You are riding on your bike and stop pedaling, coasting along the road. Eventually, your bike slows down and stops. What happened to the energy of your motion when your bike stopped?

It was released as heat.

A major difference between prokaryotic and eukaryotic cells is that __________.

Organelles are membrane-bound structures that perform specific functions. Prokaryotic cells do not have organelles.

Ribosomal subunits are manufactured by the _____.

Ribosome Ribosomes are manufactured by the nucleolus.

_____ are the sites of protein synthesis.

Ribosomes Ribosomes are the site of protein synthesis.

Diffusion is an example of ________.

passive transport

Which of these organelles produces H2O2 as a by-product?

peroxisome Peroxisomes produce hydrogen peroxide as a by-product of their metabolic processes.

ATP energizes other molecules in cells by transferring a(n) ________ to those molecules.

phosphate group

________ are the major lipids of plasma membranes.

phospholipids

You find a cell of a type you have never seen before. The cell has both a nucleus and a cell wall. Therefore, you conclude that it is likely to be a(n) ________ cell.

plant

When using a microscope to view cells you obtained from scraping under your fingernails, you notice that the cells lack nuclei; therefore, you conclude that the cells must be a type of ________ cell.

prokaryotic

Which is a function of the Golgi apparatus?

protein modification

Usually, enzymes are ________.

proteins

Which of the following are the two main components of cellular membranes?

proteins and phospholipids Proteins and phospholipids are the two major components of cellular membranes.

The Nucleus, DNA, and Chromosomes

The nucleus contains DNA organized into chromosomes. The nucleus directs most activities of the cell and is surrounded by a nuclear envelope. Nuclear pores allow materials, such as RNA, to pass out of the nucleus.

Polypeptides are assembled from _____.

amino acids Proteins are composed of amino acid monomers.

Which one of the following groups is composed of prokaryotic cells?

bacteria Bacteria and archaea both have prokaryotic cells.

_____ is/are identical in structure to centrioles.

basal bodies Basal bodies and centrioles have identical structures.

In a hypotonic solution, a plant cell will ________.

become turgid

Plant cells, unlike animal cells, are characterized by the presence of a ________.

cell wall and a central vacuole

When two solutions that differ in solute concentration are placed on either side of a selectively permeable membrane, and osmosis is allowed to take place, the water will ________.

exhibit a net movement to the side with lower water concentration

Which is a feature of prokaryotic cells but NOT eukaryotic cells?

fimbriae

One difference between eukaryotic and prokaryotic cells is that eukaryotic cells ______ prokaryotic cells.

have membrane-enclosed structures called organelles, which are lacking in

Humans are both ________.

heterotrophs and consumers

In osmosis, water moves across a selectively permeable membrane toward the __________ solution; that is, toward the solution with the __________ solute concentration.

hypertonic ... greater There will be a net movement of water by osmosis from the hypotonic solution toward the hypertonic solution.

What is a gene?

A portion of DNA that contains information to produce a protein.

Which of these structures stores, modifies, and packages products?

A The Golgi apparatus modifies, stores, and packages products of the ER.

What compound directly provides energy for cellular work?

ATP

Choose the letter that indicates the organelle that contains most of a cell's DNA.

C The nucleus contains most of a cell's DNA.

The _____ is composed of DNA and protein.

Chromatin Chromatin is composed of DNA and protein.

___________ are tightly coiled bundles of DNA and protein found in the nucleus of most living cells.

Chromosomes

A balloon that is permeable to water but not to glucose contains a 10% glucose solution. A beaker contains a 5% glucose solution. Which statement correctly classifies the solutions?

The solution in the balloon is hypertonic relative to the solution in the beaker.

What is the smallest entity that exhibits all the characteristics of life?

a cell Cells are the fundamental units of life.

The nuclear envelope is composed of ______.

a double membrane

The region of an enzyme to which a substrate binds is called the ________ site.

active

An enzyme is a protein that __________.

changes the rate of a metabolic reaction without being consumed by the reaction All catalysts, including enzymes, work by accelerating the rate of chemical reactions. They do this by lowering the activation energy. Catalysts are not consumed by the reaction and are therefore used repeatedly.

Which adaptation increases the surface area of a part of a cell that is involved in cellular respiration?

cristae of a mitochondrion

In eukaryotic cells, what name is given to the region that surrounds organelles but is not found inside the nucleus?

cytoplasm

The term used to indicate the part of a eukaryotic cell where organelles are suspended in fluid is __________.

cytoplasm The cytoplasm is the fluid that fills the area between the nucleus and the plasma membrane. Provide Feedback

Enzymes increase the rate of a reaction by ________.

decreasing activation energy

Besides the nucleus, which organelles contain their own DNA and ribosomes?

mitochondria and chloroplasts Chloroplasts and mitochondria both have their own DNA and ribosomes, which supports the endosymbiotic theory that states that both of these organelles have evolved from free-living bacteria taken up by early eukaryotic cells.

Which of these organelles carries out cellular respiration?

mitochondrion Mitochondria convert the chemical energy of organic molecules to chemical energy in the form of ATP.

In some eukaryotic cells, cilia and flagella are motile cellular appendages that aid the cell in __________.

movement Interestingly, cilia and flagella have the same basic architecture. Both are involved in cell movement.

The _______ ________ is the two-layered membrane that encases the nucleus of a eukaryotic cell, separating the nucleus from the cytoplasm.

nuclear envelope

A protein-lined channel in the nuclear envelope that regulates the transportation of molecules between the nucleus and the cytoplasm is called a _______ ____.

nuclear pore

The round body that sits inside the nucleus of a eukaryotic cell and makes ribosomal subunits from proteins and ribosomal RNA is known as the _________.

nucleolus

Which structure manufactures the components of ribosomes?

nucleolus

The _______ is the most prominent membrane-bound organelle in eukaryotic cells, and it houses most of a cell's DNA.

nucleus

Where does protein synthesis take place?

on ribosomes