Download Keshara Senanayake BIO TEST STUDY GUIDE Remember to check

Keshara Senanayake
BIO TEST STUDY GUIDE
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4 macromolecules:
Carbohydrates, lipids, proteins, and nucleic acids.
-Small organic molecules (like sugar) are used as subunits to synthesize longer molecules (like starches).
-These individual subunits are called monomers
-Long chains of monomers are called polymers
-Water is important to your body because it plays a central role to break down biological molecules to
liberate subunits so your body can use them
-when complex biological molecules are made, water is a by-product
-Subunits that make up large molecules are mostly linked up by a chemical reaction called dehydration
synthesis (form by removing water) [also called condensation]. Basically a (-H) is removed from one, and a
(-OH) is removed from another creating openings in the outer electron shells of the two subunits. These
openings are filled by sharing electrons between the subunits, creating a covalent bond that links them. The
free hydrogen and hydroxyl ions then combine to form a molecule of H2O
-the reverse reaction is called hydrolysis, which can split molecules
CARBOHYDRATES are molecules composed of carbon, hydrogen, and oxygen in the general ratio of
1:2:1. All carbohydrates are water soluble sugars (such as glucose or fructose) or chains of starch (like
cellulose), that are made by stringing sugar subunits together.
>If a carbohydrate consists of just one sugar molecule, it is called a monosaccharide
>When two or more monosaccharides are linked they form a disaccharide (two sugar) or polysaccharides
(many sugar)
>carbohydrates provide energy, but some carbs like cellulose and similar molecules produce structural
support for individual cells or even entire bodies of organisms
>Most single sugars (monosaccharide) have a back of 3-7 carbon atoms. Most of the carbon atoms have
both a hydrogen (-H) and a hydroxyl group (-OH) attached to them, so the general formula is (CH2O)n. N
is the # of carbon atoms in the formula.
>When dissolved in water, such as in cytoplasm of a cell, the carbon backbone of a sugar "circles up" into a
ring.
>Glucose is the most common monosaccharide in living organisms and is the subunit of which most
polysaccharides are made of. Glucose has 6 electrons and is in the formula C6H12O6. "Fructose" and
"galactose" has the same chemical formula as glucose but different structures.
>Some other common monosaccharides are RIBOSE and DEOXYRIBOSE, which have 5 carbons.
>Ribose and deoxyribose are parts of the genetic molecules of ribonucleic acid (RNA) and
deoxyribonucleic acid (DNA) respectively
> Sugars are usually broken down easily to free energy to use elsewhere
>Disaccharides are used for short term energy (examples: sucrose [glucose + fructose], lactose [milk sugar
which is glucose + galactose], and maltose which is [glucose + glucose])
>When needed, hydrolysis is performed and it breaks down the disaccharides
>when monosaccharides come together they form polysaccharides like starch (in pants) or glycogen (in
animals)
> cellulose (like what makes up the bark of trees) is not easily digested because every other glucose is
"turned upside down" and this bond orientation prevents digestive enzymes from attacking bonds between
glucose subunits.
>cellulose is considered FIBER (or also known as roughage)
>Super hard outer coverings called CHITIN make up the exoskeleton of many insects
>some mucus and hormones are also carbs
LIPIDS
Lipids are diverse assortment of molecules, all of which share TWO important features
>lipids contain large regions composed of mostly hydrogen and carbon, with nonpolar carbon-carbon or
carbon-hydrogen bonds
>these nonpolar regions make lipids hydrophobic and insoluble in water
>some lipids are energy storing molecules, some are hormones, ect
-Lipids are classified in three major groups
1) oils, fats, and waxes (which are similar and contain only C,H, and O)
2) phospholipids, which are similar to oils but also contain phosphorus and nitrogen
3) the fused-ring family of steroids
>oils, and waxes are similar in three ways
1) they contain only carbon, hydrogen, and oxygen
2) they contain one fatty acid subunit which are long chains of carbon and hydrogen with carboxyl group (COOH) at one end
3)they normally do not have ring structures. Fats and oils are formed by dehydration synthesis from three
fatty acid subunits and one molecule of GLYCEROL, a short, three-carbon molecule with a hydroxyl group
(-OH) per carbon
>this structure of three fatty acids joined to one glycerol molecules gives fats and oils their chemical name,
triglyceride. Notice that a double bond between two carbons in the fatty subunit forms a kink in the chain.
>fats have high concentration of chemical energy
>difference between fats and oils lies in the fatty acid.
>(as we know before, hydrogen occupies all other bond positions in carbon) fats have fatty acids with all
single bonds in their carbon chain. The resulting fatty acid becomes saturated with hydrogens. It can nestle
together and become solid at room temperature
>oils are fatty acids with double bonds between some carbons so it is unsaturated , thus oil is a LIQUID in
room temperature
>oils can become hydrogenated if you break the double bonds
>waxes are like fats
-Phospholipids have water-soluble "heads" and water-insoluble "tails"
>the plasma membrane that separates the inside of the cell from the outside world contains several types of
phospholipids
>phospholipids are like oil, except that 1 of the 3 fatty acids are replaced with a phosphate group with a
short polar functional group which is usually a nitrogen containing group. Which is unlike the two fatty
acid "tails" which are insoluble in water, the phosphate-nitrogen "head" is polar or charged and is water
soluble.
>Phospholipids has a hydrophilic head attached to a hydrophobic tail
-Steroids consist of four carbon rings fused together
>steroids are structurally different from all lipids and are composed of 4 rings of carbon fused together with
various functional groups in them. ONE TYPE OF STEROID IS CALLED CHOLESTEROL. It is a vital
component of the membrane of animal cells and is used to synthesize other steroids (includes male/female
sex hormones)
-Proteins are molecules composed of one or more chains of amino acids.
>proteins perform many functions, protein ENYZMES guide almost all the chemical reactions that occur
inside the cell.
>examples: structure: collagen in skin/keratin in hair//// movement: actin and myosin in muscle/////defense:
antibodies in bloodstream///storage: zeatin in corn seeds/// signals: growth hormone in blood stream///
>>Enzymes catalyze nearly every chemical reaction in our cells. DNA polymerase (makes DNA); pepsin
(digest protein), amylase (digest carbohydrates) ATP Synthase (makes ATP)
>most cells contain hundreds of different enzymes
>proteins are polymers of amino acids.
>all amino acids have the same fundamental structure, consisting of a central carbon bonded to four
different functional groups: a nitrogen-containing amino group (-NH2) a carboxyl or carboxylic acid (COOH), a hydrogen, and a variable (represented by the letter R)
>R varies things up, 20 amino acids are commonly found in proteins of organisms
>amino acids can either be hydrophilic or hydrophobic, but when two cysteines come together they BEND
the protein chain-- by something called "disulfide bridges"
>amino acids differ in their chemical and physical properties (size, water solubility, electrical charge..)
>amino acids are joined to form chains by dehydration synthesis. The nitrogen of the amino group (-NH2)
of one amino acid is joined to the carbon of the carboxyl group (-COOH) of another amino acid by a single
covalent bond. This bond is called a peptide bond, and the resulting chain of two amino acids is called a
peptide.
>polypeptide is used to refer to long chains of amino acids
>A protein can have up to four levels of structure
1) Primary structure: is a sequence of amino acids that make up the protein. This sequence is coded by the
genes. Different types of proteins have different sequences of amino acids.
2) Secondary structures: Hydrogen bonds may cause many proteins to form secondary structures. Many
proteins, such as keratin (hair protein) have coiled spring like secondary structures called Helix. -C=O and N-H, the negative of O and + of H holds the Helix together
3) Tertiary structure: complex three dimensional structures.
4)Quaternary structures: fourth level of protein organization; peptides may sometimes join in aggregations
to form this level
-Nucleic acids are long chains of similar but not identical subunits called NUCLEOTIDES.
>all nucleotides have a three part structure
1) a five part carbon sugar (ribose or deoxyribose)
2) a phosphate group
3) a nitrogen containing base that differs among nucleotides
>there are two types of nucleotides, the ribose nucleotide (containing the sugar ribose) and the deoxyribose
nucleotide (containing the sugar deoxyribose). Deoxyribose nucleotides bond to four types of nitrogen
containing bases -- adenine, guanine, cytosine, and thymine (GC AT), same thing for Ribose nucleotides
but instead of thymine there is uracil.
>nucleotides may be strung together in long chains as nucleic acids with the phosphate group of one
nucleotide covalently bonded to the sugar of another
>the two types of nucleic acids are
1) deoxyribonucleic acid
2) ribonucleic acid
>deoxyribose nucleotides form chains millions of units long called deoxyribonucleic acid (DNA). It spells
out the genetic information needed to construct proteins of each organism. Chains of ribose nucleotides,
called ribonucleic acid (RNA) are copied from central repository of DNA in nucleus of each cell. RNA
carries DNA's genetic code into the cell's cytoplasm and directs the synthesis of proteins.
>cyclic nucleotides (cyclic AMP) carry information from the plasma membrane to other molecules in the
cell.
>cyclic AMP is synthesized when certain hormones come in contact with the plasma membrane. It then
stimulates essential reactions in the cytoplasm or nucleus.
> some nucleotides have extra phosphate groups. These di/tri phosphate nucleotides such as adenosine
triphosphate (ATP) are unstable molecules that carry energy
>nucleotides that assist guiding chemical reactions are called coenzymes (contained in vitamins)
WHAT ARE ENZYMES
-Enzymes are biological catalysts, normally proteins synthesized by living organisms. Enzymes possess the
characteristics of catalysts.
>Enzymes are normally VERY specific, catalyzing at most a few types of reactions.
>enzyme activity is regulated by the very molecules whose reaction they catalyze
>The structure of enzymes allows them to bind specific molecules and catalyze specific reactions
> enzyme function is intimately related to enzyme structure
> enzymes are proteins with complex three dimensional shapes
> each enzyme has a groove called the active site, into which reactant molecules called substrate can enter
> the active site of each enzyme has a distinctive shape and distribution of electrical charge. The active
sites shape and charge distribution are complementary to those of its substrate.
>the shape and charge of the active site forces substrates to enter and enzyme in specific orientations.
When substrate enters the active site, both substrate and active site change shape. Certain amino acids that
form the active site may temporarily bond with atoms of the substrates or electrical interaction between the
active site and substrates may distort the chemical bonds within the substrates.
>the combination of substrate selectivity, substrate orientation, temporary chemical bonds, and bond
distortion promotes the specific chemical reaction catalyzed by a particular enzyme.
>when the final reaction between the substrates are finished, the products no longer fit properly into the
active site and are expelled.
>enzymes speed up the rate of chemical reaction by series of mini reactions with low activation energies
between the substrate and enzyme.
>enzymes have very complex, three dimensional structures that are sensitive to environmental conditions
> some require specific pH and coenzymes also
> pH 7 is the best for most (pepsin uses pH 2)
> a cell might regulate the synthesis of enzymes to meet its needs
> a cell might synthesize a enzyme in its inactive form and activate when its needed.
>using feedback inhibition the activity of the enzyme is inhibited by its product or by subsequent product
produced further along in a metabolic pathway
*******not on this test***********
CELL THEORY
-theodar schwann, matthias jakob schleiden, and rudolf virchow are credited for this
-robert hooke first saw "cells" under a compound microscope by looking at very thin slices of cork
Plasma membrane generally isolated the cell's contents from the external environment, regulates the flow
of materials into and out of the cell, and it allows interaction with other cells.
>DNA in a eukaryotic cell is found in a separate membrane bound structure called the nucleus
>in a prokaryotic cell DNA is localized to a particular place in the cell called the nucleoid.
>the cytoplasm consists of all the material inside the plasma membrane and outside the DNA containing
region.
>the cytoplasm of eukaryotic cells also contains a variety of discrete membrane enclosed structures (called
organelles)
>two basic types of cells: prokaryotic and eukaryotic
>prokaryotic cells are very small and have a simple internal structure. Most are surrounded by a very stiff
cell wall. Most move using a "flagella" different in structure than those from a eukaryotic cell. Pili (surface
projections made of protein) are used to attach some types of bacteria to surfaces or to exchange genetic
material. Capsules/slime layers are polysaccharide or protein coatings that some bacteria secrete outside
their cell wall
>cytoplasm of most prokaryotic cells is relatively homogenous in appearance. They have a single circular
strand of DNA, usually coiled and attached to the plasma membrane (also concentrated in the nucleiod
region of the cell).
>they have no membrane bound organelles
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Topics On the test
Monomer/polymer (covered above)
Endothermic: reaction that needs energy to run. Product had more energy then the reactants.
Exothermic: reaction that releases energy. Reactants have more energy then the products.
Metabolic pathways: series of chemical reactions in which the product of one reaction is the substrate for
the next reaction.
Catabolic: refers to chemical reactions that result in the breakdown of more complex organic molecules
into simpler substances. They usually release energy that is used to drive chemical reactions. The energy of
catabolic reaction is used to drive anabolic reactions. (EXOTHERMIC REACTION)
Anabolic: refers to chemical reactions in which simpler substances are combined to form more complex
molecules. Anabolic reactions usually require energy. Anabolic reactions build new molecules and/or store
energy. (ENDOTHERMIC REACTION)
Dehydration synthesis/condensation: (covered above)
Metabolism: refers to all biochemical processes that occur with any living organism
Carbs/lipids: (covered above)
Glucose: (covered above)
Bile: found in liver, helps lipase (enzyme) break down fat globs
Lipids: (covered above)
Phosolipids (covered above)
Cellulose: (covered above)
Saturated/unsaturated: (covered above)
Trans: unhealthy, when drawn think of one hand up and one hand down (when thinking of cis, raise both
your hands up)
2 bonds that make up DNA: hydrogen bonds holds the bases and a phosphodiester bond (a group of
strong covalent bonds between a phosphate group and two 5-carbon ring carbohydrates, they make up the
backbone of each helical strand)
difference between RNA and DNA: uracil instead of thymine in RNA
polypeptides: (covered above)
building blocks/monomers (covered above)
myosin/actin: protein in muscle. MOVEMENT
Insulin: peptide hormone produced by the pancreas to regular glucose in the blood. Its balanced by
GLUCAGON which is a peptide protein released by the pancreas to raise blood glucose levels
Hemoglobin: a red protein responsible for transporting oxygen in the blood /side note hemoglobin can
form a quaternary (4th) structure. It consist of two pairs of very similar peptides held together by hydrogen
bonds. Each peptide holds an iron-containing organic molecule called a heme that can bind one molecule of
oxygen.
Enzymes (covered above)
Levels of organization of polypeptide (covered above)
inhibition (covered above)
Vitamins A, B9, C, D3
Retinol (Vitamin A): vision, comes from eggs, meat, dairy, beta carotene.
Folic Acid (Vitamin B9)- transfers CH3 to DNA polymerase. Folic acid is crucial for brain
function and mental health. It is essential for pregnant women, from beans, legumes, pork
Ascorbic Acid (vitamin C)- "Helps" collagenase make collagen. Helps the growth and repair of
tissues all over your body, citrus fruits, green peppers, tomatoes
Calcitrol (Vitamin D)- regulates Ca2+, P04- in gene expression. Can be gained from sunlight
and works with calcium, the bone is a large depot of this
Tocopherol (Vitamin E)- Vitamin E is a fat-soluble vitamin found in many foods, fats, and oils. It is
also an antioxidant, a substance that may help prevent damage to the body's cells. Antioxidants may
provide protection against serious diseases including heart disease and cancer.
Phylloquinine- (Vitamin K)- its used so your body stores it in fat tissue and the liver. It is best known
for its role in helping blood clot, or coagulate, properly. Vitamin K also plays an important role in bone
health. Found in leafy green foods, the bacteria in your intestines can make vitamin K.