Nutrition Flashcards
(212 cards)
1
Q
The organ in a digestive tract that receives food from the oral cavity; in terrestrial vertebrates, the throat region where the air and food passages cross.
A
Pharynx
2
Q
A chain of amino acids linked by peptide bonds.
A
Polypeptide
3
Q
Can the urinary reclaim water?
A
Yes.
4
Q
The opening through which undigested materials are expelled.
A
Anus
5
Q
What contains considerable potential energy that could be used for a variety of purposes when released in ATP?
A
The third phosphate that is combined with ADP.
6
Q
The terminal portion of the large intestine, where the feces are stored until they are eliminated.
A
Rectum
7
Q
A chemical reaction in which a monomer is joined to another monomer or polymer, forming a larger molecule and releasing a molecule of water.
A
Dehydration Synthesis Reaction
8
Q
An attraction between two atoms resulting from a sharing of outer-shell electrons or the presence of opposite charges on the atoms. The bonded atoms gain complete outer electron shells.
A
Chemical Bonds
9
Q
What is the most common form of malnutrition?
A
The most common form of malnutrition is protein deficiency, the insufficient intake of essential amino acids.
10
Q
How do water molecules align themselves?
A
Water molecules tend to align themselves so that a negatively charged oxygen faces a positively charged hydrogen from another water molecule.
11
Q
An attraction between two ions with opposite electrical charges. The electrical attraction of the opposite charges holds the ions together.
A
Ionic Bonds
12
Q
The longest section of the alimentary canal. It is the principal site of the enzymatic hydrolysis of food molecules and absorption of nutrients.
A
Small Intestine
13
Q
What often determines the overall properties of an organic compound?
A
Functional groups.
14
Q
How many bonds can carbon form?
A
Four.
15
Q
An organelle found in plants and photosynthetic protists. Enclosed by two concentric membranes, a — absorbs sunlight and uses it to power the synthesis of organic food molecules (sugars).
A
Chloroplasts
16
Q
A monosaccharide with the chemical formula C6H12O6 found in many fruits; also called fruit sugar.
A
Fructose
17
Q
Can water always flow through a membrane?
A
No. It might require a protein channel.
18
Q
A chemical compound containing the element carbon and usually synthesized by cells.
A
Organic Compounds
19
Q
An organ that stores bile and releases it as needed into the small intestine.
A
Gallbladder
20
Q
One of two or more molecules with the same molecular formula but different structures and thus different properties.
A
Isomers
21
Q
One of many microscopic projections on the epithelial cells in the lumen of the small intestine. — increase the surface area of the small intestine.
A
Microvilli
22
Q
What happens during the citric acid cycle?
A
The citric acid cycle takes place in the fluid within mitochondria. It completes the burning of glucose, breaking down pyruvic acid to CO2, which is released from the cell. A bit of ATP is produced along with several high-energy electrons, which are carried by additional molecules of NADH as well as a molecule called FADH2.
23
Q
What determines the overall structure of a protein?
A
The specific order of the amino acids.
24
Q
What stores a lot of energy within a triglyceride?
A
Within a triglyceride, the carbon/hydrogen chains in the fatty acid tails store a lot of energy.
25
What are two ways eating a well-balanced diet helps one's body?
It provides the building materials needed for the body’s structures, and it provides the energy needed to maintain the body’s functions.
26
A giant molecule formed by joining smaller molecules. Examples of --- include proteins, polysaccharides, and nucleic acids.
Macromolecules
27
All proteins are...
polymers made by joining many amino acids together.
28
Also called a --- covalent bond; a covalent bond between atoms that differ in their attraction to electrons. The shared electrons are pulled closer to one atom, making it slightly negative and the other slightly positive.
Polar Bond
29
The steady state of body functioning; the tendency to maintain relatively constant conditions in the internal environment even when the external environment changes.
Homeostasis
30
An amino acid that an animal cannot synthesize itself and must obtain from food. Eight amino acids are essential for the human adult.
Essential Amino Acids
31
The liquid in the environment that surrounds the outside of a cell.
Extracellular Fluid
32
The tubular portion of the vertebrate alimentary canal between the small intestine and the anus.
Large Intestine
33
The organ system consisting of the skin and related structures (hair, nails, etc.) that helps protect the body.
Integumentary System
34
A type of lipid whose carbon skeleton is in the form of four fused rings: three 6-sided rings and one 5-sided ring. Examples are cholesterol, testosterone, and estrogen.
Steroids
35
Every carbohydrate consists of...
one or more monosaccharides.
36
A control mechanism in which a chemical reaction, metabolic pathway, or hormone-secreting gland is inhibited by the products of the reaction, pathway, or gland. As the concentration of the products builds up, the product molecules themselves inhibit the process that produced them.
Negative Feedback
37
What measures the amount of energy burned by one's body as it performs an activity?
Kilocalories.
38
A chemical subunit that serves as a building block of a polymer.
Monomers
39
How many naturally occurring elements make up the vast majority of matter within a living organism?
Four of the 92 naturally occurring elements make up the vast majority of matter within living organisms.
40
What happens during a chemical reaction?
During a chemical reaction, atoms gain, release, or share electrons with other atoms.
41
An attraction between atoms that share one or more pairs of outer-shell electrons.
Covalent Bonds
42
A six-carbon monosaccharide that serves as a building block for many polysaccharides and whose oxidation in cellular respiration is a major source of ATP for cells.
Glucose
43
Unsaturated fatty acids produced by the partial hydrogenation of vegetable oils and present in hardened vegetable oils, most margarines, many commercial baked foods, and many fried foods.
Trans Fat
44
A listing of all the elements ordered by their atomic number. Each entry in the --- typically contains the element symbol, its atomic mass, and its atomic number.
Periodic Table of the Elements
45
An eating disorder that results in self-starvation due to an intense fear of gaining weight, even when the person is underweight.
Anorexia Nervosa
46
A variant form of an atom. An --- of an element has the same number of protons and electrons but a different number of neutrons.
Isotopes
47
What happens during glycolysis?
Glycolysis, which takes place in the cytoplasm, involves the splitting of one molecule of glucose into two molecules of pyruvic acid. This produces a bit of ATP and some high-energy electrons carried by a molecule called NADH.
48
A large polysaccharide composed of many glucose monomers linked into cable-like fibrils that provide structural support in plant cell walls. Because --- cannot be digested by animals, it acts as fiber, or roughage, in the diet.
Cellulose
49
How much of the world is affected by hunger?
1 billion people.
50
What are the four classes of large organic molecules that are particularly important to life?
Carbohydrates, lipids, proteins, and nucleic acids.
51
A structural polysaccharide found in many fungal cell walls and in the exoskeleton of arthropods.
Chitin
52
Besides water, what makes up most of the molecules of living matter?
Organic Compounds.
53
The breakdown by enzymes of large food molecules into the smaller molecules that make them up. --- begins in the mouth and continues throughout the alimentary canal.
Chemical Digestion
54
Protons, neutrons, and electrons; particles smaller than an atom.
Subatomic Particles
55
A subatomic particle with a single unit of positive electrical charge, found in the nucleus of an atom.
Protons
56
The process of converting unsaturated fats to saturated fats by adding hydrogen.
Hydrogenation
57
Why is it called fluid mosaic?
Fluid because the molecules can move freely past one another, and a mosaic because of the diversity of proteins that float like icebergs in the phospholipid sea.
58
Where does glycolysis occur?
The cytoplasm.
59
What are the most diverse biological molecules?
Proteins.
60
The transport of large substances into the cell is usually accomplished via...
endocytosis.
61
An opening through which food is taken into an animal’s body; also known as the mouth.
Oral Cavity
62
A fat molecule in which all carbons in the hydrocarbon tails are connected by single bonds and the maximum number of hydrogen atoms are attached to the carbon skeleton. --- solidify at room temperature and are more commonly found in animal products. They are less healthy.
Saturated Fats
63
The smallest kind of sugar molecule; a single-unit sugar; also known as a simple sugar. --- are the building blocks of more complex sugars and polysaccharides.
Monosaccharides
64
The uptake of small nutrient molecules by an organism’s own body. In animals, --- is the third main stage of food processing, following digestion; in fungi, it is acquisition of nutrients from the surrounding medium.
Absorption
65
An enzyme present in gastric juice that begins the hydrolysis of proteins.
Pepsin
66
How many amino acids are there?
20.
67
What provides additional flexibility to the plasma membrane of animal cells?
Molecules of cholesterol within the phospholipid bilayer.
68
The metabolic cycle that occurs after glycolysis in cellular respiration. Chemical reactions in the cycle complete the metabolic breakdown of glucose molecules to carbon dioxide. The cycle occurs in the matrix of mitochondria and supplies most of the NADH molecules that carry energy to the electron transport chains. Also referred to as the Krebs cycle.
Citric Acid Cycle
69
An organic molecule containing a carboxyl group, an amino group, a hydrogen group, and a variable side group; serves as the monomer of proteins.
Amino Acid
70
What portion of Americans are overweight? Obese?
About one-third of all Americans are overweight, and another one-third are obese.
71
How does endocytosis work?
Substances to be ingested are packaged into vesicles that bud inward from the plasma membrane. The vesicle then travels through the cytoplasm to its destination.
72
How many people die of diabetes worldwide?
3 million.
73
How often is dialysis required?
4 to 6 hours, three times a week.
74
The study of the structure of an organism and its parts.
Anatomy
75
What is the third stage of cellular respiration?
The electron transport chain.
76
A substance that an organism must absorb in preassembled form because it cannot synthesize the nutrient from any other material. Humans require vitamins, minerals, essential amino acids, and essential fatty acids.
Essential Nutrients
77
The movement of a substance across a biological membrane against its concentration gradient, aided by specific transport proteins and requiring the input of energy (often as ATP).
Active Transport
78
What is essential in the formation of nerve signals?
The active transport of ions.
79
What do proteins do in the plasma membrane?
Most membranes have proteins embedded within them. Some of these proteins help regulate the passage of material into and out of the cell. Others aid in communication between neighboring cells, facilitate chemical reactions, or help anchor the cell or its components.
80
An excessively high body mass index, a ratio weight to height.
Obesity
81
A digestive tube running between a mouth and an anus; also called a digestive tract.
Alimentary Canal
82
Fat with hydrocarbon chains that lack the maximum number of hydrogen atoms and therefore have one or more double covalent bonds. Because of their bent shape, --- and fatty acids tend to stay liquid at room temperature. Usually found in greatest quantities in vegetable and fish oils. These are healthier.
Unsaturated Fats
83
The mechanical and chemical breakdown of food into molecules small enough for the body to absorb; the second stage of food processing, following ingestion.
Digestion
84
A dietary fat that consists of a molecule of glycerol linked to three molecules of fatty acids.
Triglyceride
85
The control of the gain or loss of water and dissolved solutes in an organism.
Osmoregulation
86
Chemical digestion uses...
hydrolysis.
87
The organ system that forms and excretes urine while regulating the amount of water and ions in the body fluids.
Urinary System
88
The total of all chemical reactions in an organism.
Metabolism
89
What causes the phospholipids to organize themselves?
Because the heads of phospholipids are hydrophilic but the tails are hydrophobic, phospholipids will spontaneously organize themselves into a two-layered membrane.
90
A steroid that is an important component of animal cell membranes and that acts as a precursor molecule for the synthesis of other steroids, such as hormones.
Cholesterol
91
The waste output of the urinary system consisting of water and dissolved wastes.
Urine
92
Does active transport require energy expenditure by the cell?
Yes.
93
The covalent linkage between two amino acids units in a polypeptide, formed by a dehydration synthesis reaction between two amino acids.
Peptide Bonds
94
An unsaturated fatty acid that an animal needs but cannot make.
Essential Fatty Acids
95
A six-carbon monosaccharide that serves as a building block for many polysaccharides and whose oxidation in cellular respiration is a major source of ATP for cells.
Glucose
96
A double covalent bond; the sharing of two pairs of electrons by two atoms. (Represented by a pair of solid lines).
Double Bond
97
A gland with dual functions: The nonendocrine portion secrete digestive enzymes and an alkaline solution into the small intestine via a duct; the endocrine portion secretes the hormones insulin and glucagon into the blood.
Pancreas
98
A type of weak chemical bond formed when a partially positive hydrogen atom from one polar molecule is attracted to the partially negative atom in another molecule (or in another part of the same molecule).
Hydrogen Bond
99
Separation and disposal of metabolic wastes from the blood by mechanical means; an artificial method of performing the functions of the kidneys.
Dialysis
100
How many people have an eating disorder in America?
Millions.
101
What are some treatments for eating disorders?
Treatment options include counseling and antidepressant medications. Some people who have anorexia and bulimia eventually develop healthy eating habits without treatment.
102
A sugar molecule consisting of two monosaccharides linked by a dehydration synthesis reaction.
Disaccharides
103
The anaerobic harvest of food by some cells.
Fermentation
104
A molecule that is constituent of the inner bilayer of biological membranes, having a hydrophilic head and a hydrophobic tail.
Phospholipid
105
A disaccharide (double sugar) made by combining a molecule of glucose with a molecule of galactose; commonly called “milk sugar”.
Lactose
106
How many stages is the process of converting food into energy?
Four.
107
The aerobic harvesting or energy from food molecules; the energy-releasing chemical breakdown of food molecules, such as glucose, and the storage of potential energy in a form that cells can use to perform work; involves glycolysis, the citric acid cycle, the electron transport chain, and chemiosmosis.
Cellular Respiration
108
What part of phospholipids are hydrophilic?
The heads.
109
The passage of a substance across a biological membrane down its concentration gradient, aided by specific transport proteins.
Facilitated Diffusion
110
A disaccharide (double sugar) made by combining two molecules of glucose.
Maltose
111
Where are excess calories stored?
Fatty foods have many calories, and excess calories in the body are stored by adding triglycerides to adipose tissue, also called body fat.
112
A disaccharide (double sugar) made by combining a molecule of glucose with a molecule of fructose; --- is common table sugar.
Sucrose
113
What is the end result after the kidneys filtered the blood?
Urine.
114
The fluid part of the cytoplasm, in which organelles are suspended.
Cytosol
115
Does every organism exchange chemicals and energy with its surroundings?
Yes.
116
What is the most important function of the plasma membrane?
Plasma membranes regulate the passage of materials into and out of the cells.
117
The act of eating; the first stage of food processing.
Ingestion
118
A subatomic particle with a single unit of negative electrical charge. One or more --- move around the nucleus of an atom.
Electrons
119
Passive transport occurs when...
a substance moves across a membrane from an area where its concentration is higher to an area where its concentration is lower.
120
Carbohydrates are...
an important source of dietary energy for animals and a key structural component of plants.
121
How does exocytosis work?
Vesicles containing the material to be exported fuse with the plasma membrane, dumping into the environment around the cell.
122
Organs that interfaces with the alimentary canal of the digestive system. --- add digestive chemicals to the alimentary canal.
Accessory Organs
123
An atom or molecule that has gained or lost one or more electrons, thus acquiring an electrical charge.
Ions
124
A flap of elastic cartilage that protects the entrance to the trachea. Normally, the --- is positioned to allow air to enter the trachea; it changes position when food is swallowed, allowing food to enter the esophagus and preventing food from entering the trachea.
Epiglottis
125
What causes microoraganisms to taste sharp?
Lactic acid.
126
What are the two basic varieties of dietary fats?
Saturated and Unsaturated.
127
The process by which plants, algae, and some bacteria transform light energy to chemical energy stored in the bonds of sugars. This process requires an input of carbon dioxide and water and produces oxygen gas as a waste product.
Photosynthesis
128
A group of atoms that form the chemically reactive part of an organic molecule. A particular --- usually behaves similarly in different chemical reactions.
Functional Groups
129
Does passive transport require energy expenditure by the cell?
No.
130
The study of the human body reveals one of the fundamental principles of biology:
the correlation of form and function.
131
A biological polymer constructed from amino acid monomers.
Proteins
132
Active transport is usually driven by...
a protein that sits within the membrane.
133
What is the amount of chemical energy stored in food measured in?
Kilocalories (kcal).
134
Also called a --- covalent bond; a covalent bond in which electrons are shared equally between two atoms of similar electronegativity; the resulting bond does not have a positive and negative pole; the opposite of a polar bond.
Nonpolar Bond
135
An eating disorder characterized by episodic binge eating followed by purging through induced vomiting, abuse of laxatives, or excessive exercise.
Bulimia
136
What serves as the basic skeletons for a wide variety of chemical compounds?
Carbon
137
The collection of fluids secreted by the epithelium lining the stomach.
Gastric Juice
138
What are the waste products of cellular respiration?
Carbon dioxide, water, and heat are released as waste products.
139
What part of phospholipids are hydrophobic?
The tails.
140
An atom’s central core, containing protons and neutrons. The genetic control center of a eukaryotic cell.
Nucleus
141
A large polysaccharide composed of many glucose monomers linked into cable-like fibrils that provide structural support in plant cell walls. Because --- cannot be digested by animals, it acts as fiber, or roughage, in the diet.
Cellulose
142
A complex, extensively branched polysaccharide made up of many glucose monomers; serves as an energy-storage molecule in the liver and muscle cells.
Glycogen
143
Fermentation results in...
the production of a variety of end products depending on the organism doing the fermenting, but each type of fermentation recycles molecules of NAD+ that can then be used for more glycolysis.
144
A single covalent bond; the sharing of one pair of electrons by two atoms. (Represented by solid line).
Single Bond
145
A double layer of phospholipid molecules (each molecule consisting of a phosphate group bonded to two fatty acids) that is the primary component of all cellular membranes.
Phospholipid Bilayers
146
The absence of one or more essential nutrients from the diet.
Malnutrition
147
A storage polysaccharide found in the roots of plants and certain other cells; a polymer of glucose.
Starch
148
What is in a well-balanced diet?
A well-balanced diet is rich in whole grains, fruits, and vegetables, with moderate amounts of lean meat and low-fat dairy, and limited quantities of saturated fats, sugars, and salt.
149
A biological molecule consisting of a simple sugar (a monosaccharide), two monosaccharides joined into a double sugar (a disaccharide), or a chain of monosaccharides (a polysaccharide).
Carbohydrates
150
The study of the function of an organism’s structural equipment.
Physiology
151
What is the nutritional imbalance of greatest concern in America?
Obesity.
152
How does water flow?
Water always flows from an area of higher water concentration to an area of lower water concentration.
153
Also called the atomic mass; the total mass of an atom which is the mass in grams of 1 mole of the atom.
Atomic Weight
154
Where does most food energy come from?
One obtains most of their food energy from other carbohydrates, fats, and proteins rather than from glucose.
155
The spontaneous movement of particles of any kind down a concentration gradient; that is, movement of particles from where they are more concentrated to where they are less concentrated.
Diffusion
156
A ratio of weight to height used as a measure of obesity.
Body Mass Index (BMI)
157
The tubular excretory unit and associated blood vessels of the vertebrate kidney. The --- extracts filtrate from the blood and refines it into urine.
Nephron
158
The number of protons in each atom of a particular element.
Atomic Number
159
What is the central currency of one's metabolism?
ATP. All food energy leads to it, and all bodily work is powered by it.
160
Many important metabolic reactions involve...
the breaking down and building up of polymers.
161
The movement of material out of the cytoplasm of a cell via membranous vesicles or vacuoles.
Exocytosis
162
What is the first stage of cellular respiration?
Glycolysis.
163
The channel through which food passes in a digestive tube, connecting the pharynx to the stomach.
Esophagus
164
An organic nutrient that an organism requires in very small quantities. Many --- serve as coenzymes or parts of coenzymes.
Vitamins
165
What happens during anaerobic exercise?
During anaerobic exercise, one’s muscles switch to an “emergency mode” in which glucose is fermented to produce lactic acid and a bit of ATP—much less ATP than is made via aerobic cellular respiration.
166
The movement of materials from the external environment into the cytoplasm of a cell via vesicles or vacuoles.
Endocytosis
167
A solution of salts secreted by the liver that emulsifies fats and aids in their digestion.
Bile
168
The passing of undigested material out of the digestive compartment; the fourth stage of food processing, following absorption.
Elimination
169
The total of all chemical reactions in an organism.
Metabolism
170
A type of connective tissue in which the cells contain fat.
Adipose Tissue
171
A finger-like projection of the inner surface of the small intestine. A finger-like projection of the chorion of the mammalian placenta. Large numbers of --- increase the surface areas of these organs.
Villi
172
The breakdown of glucose always begins with...
glycolysis.
173
Adenosine diphosphate, a molecule composed of adenosine and two phosphate groups. The molecule ATP is made by combining a molecule of ADP with a third phosphate in an energy-consuming reaction.
ADP
174
A description of membrane structure, depicting a cellular membrane as a mosaic of diverse protein molecules embedded in a fluid bilayer of phospholipid molecules.
Fluid Mosaic
175
The organ system involved in ingestion of food, digestion, absorption of nutrients into body cells, and elimination of wastes.
Digestive System
176
An organic compound consisting mainly of carbon and hydrogen atoms linked by nonpolar covalent bonds and therefore mostly hydrophobic and insoluble in water. --- include fats, waxes, phospholipids, and steroids.
Lipids
177
The largest organ in the vertebrate body. The --- performs diverse functions, such as producing bile, preparing nitrogenous wastes for disposal, and detoxifying poisonous chemicals in the blood.
Liver
178
An electrically neutral particle found in the nucleus of an atom.
Neutrons
179
Also called the atomic symbol, an abbreviation for the name of an element found within the periodic table.
Symbol
180
An organelle in eukaryotic cells where cellular respiration occurs. Enclosed by two concentric membranes, it is where most of the cell’s ATP is made.
Mitochondria
181
A series of chemical reactions controlled by enzymes in which organic molecules (often the sugar glucose) are broken down through the use of oxygen to produce energy in the form of molecules of ATP.
Aerobic Respiration
182
What does ATP come from?
Glucose.
183
A group of essential fatty acids, consumption of which in the diet is required for proper health.
Omega-3 Fatty Acids
184
Larger nutrient molecules in food are...
never used directly.
185
In nutrition, a simple inorganic nutrient that an organism requires in small amounts for proper body functioning.
Minerals
186
What are some health problems that come from obesity?
Obesity contributes to a number of health problems, including type 2 diabetes, 15 kinds of cancer, and cardiovascular disease.
187
How do cells maintain a relatively constant internal environment even when the external environment changes?
By using its plasma membrane.
188
What is the central hub of the urinary system?
The kidneys.
189
What causes eating disorders?
The precise causes of anorexia and bulimia are unknown, although genetics, psychology, and brain chemistry all appear to play a role. Culture also seems to be a factor.
190
What does yeast produce as it ferments?
CO2 and ethyl alcohol (ethanol).
191
Physical process, such as chewing, that helps break food down into smaller molecules.
Mechanical Digestion
192
What causes the plasma membrane to flex and undulate?
The phospholipid bilayer and most of the proteins in it drift about in the plane of the membrane.
193
The diffusion of water across a selectively permeable membrane.
Osmosis
194
What type of bond holds atoms together in a molecule?
Covalent bonds.
195
“Water-fearing”; pertaining to nonpolar molecules (or parts of molecules), which do not dissolve in water.
Hydrophobic
196
Rhythmic waves of contraction of smooth muscles. --- propels food through a digestive tube and also enables many animals, such as earthworms, to crawl.
Peristalsis
197
What is the most common isotope of nitrogen?
NItrogen-15
198
Adenosine triphosphate, a molecule composed of adenosine and three phosphate groups; the main energy source for cells. A molecule of ATP can be broken down to a molecule of ADP (adenosine diphosphate) and free phosphate; this reaction releases energy that can be used for cellular work.
ATP
199
Passive transport is said to occur along a...
concentration gradient.
200
What are the risks of trans fats?
Trans fats are quite unhealthy, increasing the risk of heart disease, diabetes, and high blood pressure.
201
How long can anaerobic exercise last?
A few minutes.
202
An element that is essential for the survival of an organism but is needed in only minute quantities.
Trace Elements
203
Ionic bonds involve...
the transfer of one or more electrons from one atom to another.
204
A large molecule consisting of many identical or similar molecular units, called monomers, covalently joined together in a chain.
Polymers
205
What is the second stage of cellular respiration?
The citric acid cycle.
206
What two organelles play key roles in providing energy?
Chloroplasts and mitochondria.
207
What are examples of trace elements?
Iron, zinc, copper, chromium, selenium, iodine, fluorine, manganese, molybdenum, cobalt, nickel, tin, silicon, vanadium, and arsenic
208
Chemical reaction in which macromolecules are broken down by the chemical addition of water molecules to the bonds linking their monomers. A --- is the opposite of a dehydration synthesis reaction.
Hydrolysis Reactions
209
What can cause kidney failure?
Kidney failure, the inability of the kidneys to filter blood, can be caused by injury, illness, or prolonged use of pain relievers, alcohol, or other drugs.
210
A synthetic variant of the male hormone testosterone that mimics some of its effects.
Anabolic Steroids
211
What provides the energy that powers most ecosystems on Earth?
The sugars produced by photosynthesis.
212
A carbohydrate polymer consisting of many monosaccharides (sugars) linked by covalent bonds.
Polysaccharides
