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The chemical substances and processes that occur in plants, animals, and microorganisms and of the changes they undergo during development and life.

chemical processes

living organisms

molecular level





human health




james watson

A cell targets itself.

  • Autocrine

Almost all of the enzymes of the citric acid cycle are soluble, with the single exception of the enzyme ______, which is embedded in the inner membrane of the mitochondrion.

  • succinate dehydrogenase

Which end of the water molecule has a slightly positive charge?

  • the carbon dioxide end
  • the oxygen end
  • the hydrogen end

Almost all of the enzymes of the citric acid cycle are soluble, with the single exception of the enzyme _______, which is embedded in the inner membrane of the mitochondrion.

  • succinate dehydrogenase

Chemical signals are released by ______ in the form of small, usually volatile or soluble molecules called ligands.

  • signaling cells

________ also regulates pain sensation and inflammatory responses.

  • [No Answer]

Through a series of steps, citrate is _____, releasing two carbon dioxide molecules for each acetyl group fed into the cycle.

  • oxidized

Signals from distant cells are called endocrine signals, and they originate from ________.

  • endocrine cells

It is the process of making RNA from DNA template where the code in the DNA is

  • Transcription

The reaction used to digest and break the bond in red is ___________.

  • carbohydrates
  • hydrolysis
  • hydrogen

What is the tetrameric protein that transports oxygen?

  • Hemoglobin

The neurotransmitters that are released into the chemical synapse are degraded quickly or get reabsorbed by the ______ so that the recipient nerve cell can recover quickly and be prepared to respond rapidly to the next synaptic signal.

  • presynaptic cell

Which matured cells in the human body do not contain nucleic acids

  • [No Answer]

______ are produced by signaling cells that can also bind to the ligand that is released.

  • autocrine signals

The ratio of 1:2:1 is one of the properties of disaccharide.

  • True
  • False

CoA is bound to a _____ (-SH) and diffuses away to eventually combine with another acetyl group.

  • sulfhydryl group

The ligands released in endocrine signaling are called ________, signaling molecules that are produced in one part of the body but affect other body regions some distance away.

  • hormones

When a piece of liver is dropped into hydrogen peroxide, the peroxide bubbles vigorously as the hydrogen peroxide decomposes into water and oxygen. This rapid change in reaction rate suggests ________________.

  • the liver contains an enzyme that increases hydrogen peroxide
  • the liver contains an enzyme that breaks down hydrogen peroxide
  • the gall bladder contains an enzyme that breaks down hydrogen peroxide
  • the liver contains an enzyme that decreases hydrogen peroxide

Which one is the active site?

  • A
  • B
  • C
  • E
  • D

There are four categories of chemical signaling found in multicellular organisms: paracrine signaling, endocrine signaling, autocrine signaling, and __________.

  • direct signaling across gap junctions

Which one is enzyme?

  • A
  • C
  • D
  • E
  • B

The distance between the presynaptic cell and the postsynaptic cell—called the ______ —is very small and allows for rapid diffusion of the neurotransmitter.

  • synaptic gap

Attractions between water molecules are called _____________.

  • molecular bonds
  • nuclear bonds
  • hydrogen bonds

When the neurotransmitter binds the _____ on the surface of the postsynaptic cell, the electrochemical potential of the target cell changes, and the next electrical impulse is launched.

  • receptor

What protein substances catalyze biochemical reactions?

  • Enzymes

When collagen is denatured by heat, it turns into?

  • Gelatin

This refers to the long chains of carbon hydrogen bonds containing carbon, hydrogen, and oxygen.

  • [No Answer]

If ATP is in ________________, the rate increases.

  • short supply

Signaling via gap junctions involves signaling molecules moving directly between ______.

  • adjacent cells

The enzyme that catalyzes step four is regulated by ________________ of ATP, succinyl CoA, and NADH.

  • feedback inhibition

Which one is substrate?

  • E
  • A
  • C
  • B
  • D

What is the storage protein that is bonded with iron to store iron in the body?

  • Ferritin

Step six is a dehydration process that converts _________________.

  • succinate into fumarate

Which group of amino acids can be synthesized by the body and may not be the requisite components of the diet?

  • [No Answer]

Signals that act locally between cells that are close together are called ____.

  • paracrine signals

The chylomicrons enable fats and cholesterol to move within the ______ environment of your lymphatic and circulatory systems.

  • aqueous

Which one is not the function of lipids in the body?

  • to relieve constipation
  • to store energy
  • to form cell membrane

Removing the signals will reestablish the concentration gradient for the signal, allowing them to quickly diffuse through the ______ if released again.

  • intracellular space

As water freezes, it expands and its density decreases.

  • How do you form an ice?
  • Why is it called an ice?
  • Where is the ice?
  • Why does ice float?

A cell targets a cell connected by gap junctions.

  • Signaling across gap junctions

From the lymphatic system, the chylomicrons are transported to the _____ system.

  • circulatory

When food reaches the small intestine in the form of chyme, a digestive hormone called ______ is released by intestinal cells in the intestinal mucosa.

  • pancreozymin

A hydrocarbon chain that is sometimes considered to be a monomer of lipids.

  • amino acids
  • cholesterol
  • hyper tension
  • fatty acids

If an RNA molecule is single stranded, the DNA molecule has 2 strands, characteristically described as?

  • Double helix

This refers to the molecule in which opposite ends have opposite electric charges.

  • significant molecule
  • ion molecule
  • polar molecule
  • compound molecule

Lipid metabolism begins in the intestine where ingested triglycerides are broken down into smaller chain fatty acids and subsequently into monoglyceride molecules by pancreatic lipases, enzymes that break down fats after they are emulsified by _______.

  • [No Answer]

Name the three universal types of RNA

  • Messenger RNA (mRNA) Transfer RNA (tRNA) Ribosomal RNA (rRNA) Micro RNA (miRNA)

Lipid metabolism is associated with carbohydrate metabolism, as products of ______ (such as acetyl CoA) can be converted into lipids.

  • glucose

This molecules is a ______________.

  • fats
  • carbohydrate
  • protein
  • vitamin E

Name the 2 types of nucleic acids

  • DNA and RNA

GTP is energetically equivalent to _______________________.

  • ATP

What word describes when water is attracted to other substances?

  • exhaustion
  • suspension
  • perspiration
  • adhesion

One example of paracrine signaling is the transfer of signals across ______ between nerve cells.

  • synapses

What macromolecule is this?

  • carbohydrate
  • lipid
  • protein
  • amylase

Fats (or triglycerides) within the body are ingested as food or synthesized by adipocytes or hepatocytes from _____ precursors.

  • carbohydrate

Hormones travel the large distances between endocrine cells and their target cells via the ______, which is a relatively slow way to move throughout the body.

  • bloodstream

Unsaturated fats are ______________ at room temperature.

  • liquids
  • carbohydrates
  • gas
  • solid

A cell targets a distant cell through the bloodstream.

  • Endocrine

Some enzymes exist in their inactive forms and are known?

  • proenzyme

Which vitamin play an important role in the synthesis of collagen?

  • Vitamin C

The glycerol that is released from triglycerides after lipolysis directly enters the glycolysis pathway as _____.

  • DHAP

Saturated fats are ____________ at room temperature.

  • solid
  • liquid
  • gas

The sequence of amino acids is determined by ___________.

  • complexion
  • genes
  • hairiness
  • structure

This is also water's ability to be attraction to other water molecules.

  • adhesion
  • cohesion
  • suspension

He discovered nucleic acids in 1869

  • Friedrich Miescher

What is the purpose of an enzyme?

  • incorporate reaction process
  • decreases reaction process
  • motivate reaction process
  • speed up reactions

What do you call the DNA segments that carry the genetic information?

  • Genes

CCK also travels to the brain, where it can act as a _____.

  • [No Answer]

A ______ consists of a cell body, several short, branched extensions called dendrites that receive stimuli, and a long extension called an axon, which transmits signals to other nerve cells or muscle cells.

  • nerve cell

What are the 2 semi-essential amino acids among humans?

  • [No Answer]

With what 3 letters do enzymes typically end?

  • ase
  • use
  • ous
  • ias

The neurotransmitters are transported across the very small distances between nerve cells, which are called ______.

  • chemical synapses

The characteristic that all lipids have in common is _____________.

  • it turns into solid
  • it can be dissolved in water easily
  • it doesn't dissolve in water
  • it evaporates fast

Two __________ are transferred to FAD, producing FADH2.

  • hydrogen atoms

The synthesis of a protein from an mRNA template where the code in the mRNA is

  • translation

In ______, a cell may target itself (autocrine signaling), a cell connected by gap junctions, a nearby cell (paracrine signaling), or a distant cell (endocrine signaling).

  • chemical signaling

Each of these monomeric units of nucleic acids has three components. Name these 3 components

  • [No Answer]

What is the main function of carbohydrates?

  • restore good eyesight
  • provide energy
  • clear the skin
  • minimize pores and pimples

This is the number of amino acids used to produce proteins for all living things.

  • 10
  • 100
  • 40
  • 20

Any substance that is acted upon by an enzyme is called aNo?

  • substrate
  • active site
  • lipase
  • deactivated site

The diagram shows a bond forming between two amino acids. What is the name of the resulting bond?

  • peptide bond
  • chemical bond
  • nuclear bond
  • compound bond

In order to keep the response localized, ______ are normally quickly degraded by enzymes or removed by neighboring cells.

  • paracrine ligand molecules

Which type of compound would not dissolve easily in water?

  • polar
  • ionic
  • fats

Organisms living in a bog environment must be able to tolerate nitrogen-poor acidic conditions. Bog plants such as the Venus flytrap and sundew are able to obtain their nitrogen by attacking and consuming insects. These plants produce chemicals that break down the insects into usable compounds.

  • enzymes
  • substance
  • acid
  • chemicals

Identify the monomeric unit of nucleic acids

  • [No Answer]

How many sugar units make up disaccharides?

  • 2,000
  • 200
  • 20
  • 2

CCK stimulates the release of ________ from the pancreas and stimulates the contraction of the gallbladder to release stored bile salts into the intestine.

  • [No Answer]

In _______, a cell may target itself (autocrine signaling), a cell connected by gap junctions, a nearby cell (paracrine signaling), or a distant cell (endocrine signaling).

  • chemical signaling

Water is a universal solvent because ...

  • it doesn't dissolve a substance.
  • it dissolves a few substance.
  • it dissolves most substance.
  • it dissolves all substances.

Communication between cells is called intercellular signaling, and communication within a cell is called _______.

  • intracellular signaling

Signals within the nerve cells are propagated by fast-moving _______ impulses.

  • electrical

The attraction that causes water and other liquids to form drops on thin films is called _________________.

  • adhesion
  • cohesion
  • suspension

The shape of the enzyme molecule is changed.

  • What happens to an enzyme when it collapsed?
  • What happens to an enzyme when it combines?
  • What happens to an enzyme when it denatures?

Ligands interact with proteins in target cells, which are cells that are affected by chemical signals; these proteins are also called ______.

  • receptors

Enzymes in the ______ degrade some types of neurotransmitters to terminate the signal.

  • synaptic cleft

If ATP levels _____, the rate of this reaction decreases.

  • increase

Which of the following molecules make up the basic structure of a cell membrane?

  • amylase
  • phospholipids
  • celluloid
  • fiber

To obtain energy from _______, triglycerides must first be broken down by hydrolysis into their two principal components, fatty acids and glycerol.

  • fat

Which one would not affect the rate of enzyme activity?

  • stress
  • pH
  • temperature

Steps three and four are both ____________________, which release electrons that reduce NAD+ to NADH and release carboxyl groups that form CO2 molecules.

  • oxidation and decarboxylation steps

The breakdown of fatty acids, called fatty acid oxidation or beta (β)-oxidation, begins in the _____, where fatty acids are converted into fatty acyl CoA molecules.

  • [No Answer]

This molecule is a __________.

  • lipids
  • amylase
  • amino acid
  • glucose

Signals that act locally between cells that are close together are called ______.

  • paracrine signals

What links these monomeric units to form proteins?

  • [No Answer]

The pancreatic lipases and bile salts break down ______ into free fatty acids.

  • triglycerides

Proteins are polymers of what monomeric units?

  • Amino acids

Lipid metabolism entails the oxidation of fatty acids to either generate ______ or synthesize new lipids from smaller constituent molecules.

  • energy

All carbohydrate names end with which ending?

  • ose
  • ous
  • al
  • ic

In the citric acid cycle, the acetyl group from acetyl CoA is attached to a four-carbon oxaloacetate molecule to form a six-carbon ______.

  • citrate molecule

In the process, three _____ are reduced to NADH, one FAD molecule is reduced to FADH2, and one ATP or GTP (depending on the cell type) is produced (by substrate-level phosphorylation).

  • NAD+ molecules

Because of their form of transport, hormones get _____ and are present in low concentrations when they act on their target cells.

  • diluted

Which of the following conclusions can be drawn from this graph?

  • The optimum pH of the enzyme is 6.6.
  • The optimum pH of the enzyme is 9.0.
  • The optimum pH of the enzyme is 50.
  • The optimum pH of the enzyme is 100.

Signals that act locally between cells that are close together are called

  • paracrine signals

A water strider can skate along the top of a pond because of the hydrogen bonds result in water cohesion.

  • True
  • False

In step two, citrate loses one water molecule and gains another as citrate is converted into its isomer, _______________.

  • isocitrate

The term protein was derived from which Greek word that means “primary”?

  • Proteios

What molecule is this:

  • lipase
  • amino acid
  • glucose
  • carbon

These are all examples of lipids except one.

  • margarine
  • butter
  • olive oil
  • venison

The junction between nerve cells where signal transmission occurs is called a ________.

  • synapse

Which of these is most likely an enzyme?

  • amylase
  • iron
  • amino acid
  • protein

Which one is not an example of lipids?

  • waxes
  • steroids
  • carbohydrates
  • triglycerides

Because the final product of the citric acid cycle is also the _____, the cycle runs continuously in the presence of sufficient reactants.

  • first reactant

Which of the following is a lipid?

  • fats
  • proteins
  • cholesterol
  • sugar

What is the clinical condition wherein the 6th amino acid in the beta chain of hemoglobin is altered?

  • [No Answer]

Within the intestinal cells, these triglycerides are packaged along with cholesterol molecules in phospholipid vesicles called _______.

  • chylomicrons

These are long term energy storage which helps to form cell membranes and provides parts of other biomolecules like hormones.

  • functions of carbohydrates
  • functions of glucose
  • functions of starches
  • functions of lipids

The amino acid that results in disulphide bridges is called _______________.

  • carboxyllic acid
  • variable sie chain
  • cysteine
  • amino group

If a cell is infected with a ______, the cell can signal itself to undergo programmed cell death, killing the virus in the process. In some cases, neighboring cells of the same type are also influenced by the released ligand.

  • virus

Chemical signals are released by _______ in the form of small, usually volatile or soluble molecules called ligands.

  • signaling cells

The structure of proteins can be changed by environmental factors such as temperature or pH.

  • True
  • False

______ acts on nearby cells, endocrine signaling uses the circulatory system to transport ligands, and autocrine signaling acts on the signaling cell.

  • paracrine signaling

Ligands can thus be thought of as ______.

  • signaling molecules

Which biomolecule is often stored in the body's tissues as energy?

  • glucose
  • iron
  • phospate
  • lipids

A cell targets a nearby cell.

  • Paracrine

How do lipids function for cells?

  • use energy
  • move energy
  • store energy
  • remove energy

Where do substrates bind on an enzyme?

  • cellulose
  • deactivated site
  • active site

Like the conversion of pyruvate to acetyl CoA, the citric acid cycle takes place in the matrix of _____.

  • mitochondria

Substances on which enzymes act to convert them into products are known as?

  • Substrates

Unlike glycolysis, the citric acid cycle is a ______.

  • closed loop

The citric acid cycle produces very little ATP directly and does not directly consume ______.

  • oxygen

The main difference between the different categories of signaling is the ____ that the signal travels through the organism to reach the target cell.

  • distance

Name the group of amino acids which are not synthesized by the body and must be taken in diet.

  • Essential Amino Acids

In step five, a phosphate group is substituted for coenzyme A, and a ___________________is formed.

  • high-energy bond

Chylomicrons leave the enterocytes by exocytosis and enter the lymphatic system via ________ in the villi of the intestine.

  • lacteals

The bond that joins amino acids are called _____________.

  • peptide bonds
  • chemical bonds
  • nuclear bonds

What fraction of the total dry body weight is made up of proteins?

  • [No Answer]

Chylomicrons contain triglycerides, cholesterol molecules, and other _____ (protein molecules).

  • apolipoproteins

A ______ is a molecule that binds another specific molecule, in some cases, delivering a signal in the process.

  • ligand

The primary sequence of a protein refers to the:

  • order of amino acids
  • order of minerals
  • order of vitamins
  • order of nutrients

In step three, isocitrate is oxidized, producing a five-carbon molecule, α-____________________, together with a molecule of CO2 and two electrons, which reduce NAD+ to NADH.

  • ketoglutarate

When these impulses reach the end of the axon, the signal continues on to a dendrite of the next cell by the release of chemical ligands called ______ by the presynaptic cell (the cell emitting the signal).

  • neurotransmitters

What are the 2 basic types or models of enzyme-substrate complex formation?

  • [No Answer]

What protein is the main constituent of skin, bone, tendon, cartilage and teeth among mammals?

  • Collagen

Paracrine signals move by diffusion through the _______ matrix.

  • extracellular

Most enzymes are composed of _______________.

  • carbohydrates
  • proteins
  • calcium
  • vitamins

Signals within the nerve cells are propagated by fast-moving ____ impulses.

  • electrical

These are short term energy and structure in plants.

  • functions in carbohydrates
  • functions in protein
  • functions in vitamins
  • functions in fats

Certain enzymes require specific, thermostable, low mol. wt, non-protein organic substance called?

  • Coenzyme

Match the illustration of the form of chemical signaling.

  • paracrine, autocrine, signaling across gap junctions, endocrine

Enumerate the 5 primary nitrogenous bases in nucleic acids

  • [No Answer]

What is another name for enzyme?

  • biological catalysts
  • amino acid
  • amylase
  • lipase

Based on the graph, what is the optimal temperature for this enzyme?

  • 60ºC
  • 50ºC
  • 90ºC
  • 30ºC

A ______ is a chemical signal that travels between nerve cells.

  • synaptic signal

What type of carbohydrate is this?

  • monosaccharide
  • bisaccharide
  • polysaccharide

The enzyme in the body works at best at 37ºC.

  • True
  • False

Paracrine signals move by diffusion through the ______ matrix.

  • extracellular

Why can water have no net charge but have slight charges in different parts of the molecule?

  • The hydrogen end is slightly negative and the oxygen end is slightly positive.
  • The oxygen end is slightly negative and the hydrogen end is slightly positive.

How many sugar units make up monosaccharides?

  • 100
  • 10
  • 1
  • 1,000
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