CHARACTERISTICS OF LIFE

Ms. Fogler and Ms. DiamondBiology I

MOLECULAR STRUCTURE AND

FUNCTIONCarbohydratesProteins

LipidsNucleic Acids

CARBOHYDRATES Carbohydrates are organic molecules

composed of carbon, hydrogen, and oxygen

The simplest type is a monosaccharide, or simple sugar (glucose, galactose, fructose)

Chains of monosaccharides form polysaccharides

Starch, cellulose, and glycogen are examples

Function: sources of energy, give structure to plants, attached to the cell membrane to allow cellular communication

PROTEINS Also an organic compound Made up of amino acids Form chains by joining together by peptide

bonds to form polypeptides Proteins can be in chains, twisted/folded, or

more than one chain Function: determined by specific shape,

some are structural (building blocks of living things), some are hormones, some control cell reproduction, some act as enzymes to control cellular reactions, and some are in membranes and act as receptors or pumps.

LIPIDS Fats, oils, and waxes are examples of lipids. These are organic compounds that don’t

dissolve in water. They are made up of a glycerol molecule and

a fatty acid. Saturated have only single bonds between

the carbons and hydrogens on all sides. Unsaturated have at least one double bond

and less hydrogens Function: energy source, insulate, waterproof, transport of vitamins, and part of

cell membrane.

NUCLEIC ACIDS Function: stores genetic information Structure: large molecules made up of a

sugar, phosphate, and a nitrogenous base

Two most important nucleic acids are RNA and DNA

REVIEW1) Which of the following types of

molecules provides building blocks for tissues, transports other molecules, and helps to regulate certain reactions in the human body?

a. Lipidsb. Fatsc. Carbohydratesd. Proteins

REVIEW1) Which of the following types of

molecules have a primary function of providing a rapidly available energy source for living things?

a. Proteins b. Carbohydratesc. Fats d. Amino acids

REVIEW1) How does a saturated lipid differ from

a polyunsaturated one?a. A saturated lipid is made up of only

carbon atomsb. A saturated lipid contains only single

bonds between carbon atomsc. A saturated lipid is covalently bonded to a

protein moleculed. A saturated lipid is folded around and

bonded to itself

REVIEW1) What determines the sequence and

arrangement of amino acids in a protein?

a. The number of available atoms in an organism

b. The number of hydrogen atoms in fatty acids

c. The ratio of carbon, hydrogen, and oxygen atoms in carbohydrates

d. The information stored and translated by nucleic acids

PHOTOSYNTHESIS Organisms that make their own food are

autotrophs Organisms that cannot produce their

own food are heterotrophs Photosynthesis is conducted by

autotrophs and it is the process of producing food in the form of simple sugars from sunlight and CO2

sunlight+ 6CO2 + 6H2O C6H12O6 + 6O2

RESPIRATION Both plants and animals use energy to

run activities in the cells. Energy in food is released by respiration.

Respiration begins with the first stage of a process called glycolysis, or the breaking down of the sugar glucose.

In glycolysis, sugar is broken down into 2 pyruvic acid molecules.

The energy that drives this process comes from ATP (Adenisine Triphosphate).

RESPIRATION After glycolysis, if oxygen is present,

cellular respiration can occur and it is said to be aerobic.

C6H12O6 + 6O2 6CO2 + 6H2O + ATP

The products are carbon dioxide, water, and energy as ATP.

If oxygen is not present (anaerobic), glycolysis is followed by fermentation. Lactic Acid fermentation happens in animal cells and alcoholic fermentation happens in plant cells

REVIEW1) What occurs during the process of

photosynthesis?a. Chemical energy is converted into light

energyb. Light energy is converted into chemical

energyc. Glucose is broken down to release energyd. Carbon dioxide and energy are released

into the atmosphere

REVIEW1) Which are the essential raw materials

for photosynthesis?a. Carbon dioxide and waterb. Water and oxygenc. Glucose, water, and carbon dioxided. Glucose, oxygen, and water

REVIEW1) Which of the following is a product of

cellular respiration?a. oxygenb. Carbon dioxidec. glucosed. sunlight

PROCESSES OF DISEASE When a biological system is

compromised, the body is said to be suffering from a disease

Typically result from an infection or an intrinsic failure of a system

Types: Infectious diseases spread from pathogens like bacteria, viruses, and protists and noninfectious diseases are caused by being inherited or by things in the environment

PROCESSES OF DISEASE Causes: parasites are organisms that live

on or in another organism and cause it harm Examples where organisms cause disease:

Plasmodium vivax (protist) spread by mosquitoes causes Malaria, trypanosoma brucei (protist) spread by tsetse fly causes sleeping sickness

Examples where a toxin produced by an organism causes disease: clostridium (bacteria) causes botulism and pogomomyrmex (animal) causes venom poisoning

PROCESSES OF DISEASE Viruses are tiny pieces of genetic

material surrounded by a protein coat. They cannot reproduce unless they destroy the cells they invade. HIV, colds, the flu, and rabies are examples.

PROCESSES OF DISEASE Types of noninfectious diseases:

allergies, asthma, diabetes, cancer, and parkinson’s

Most noninfectious diseases are believed to have a genetic component, but in some cases the environment may be a cause.

Herbicides, pesticides, and water and air pollution are some examples.

Also, alcohol, drugs, tobacco can also cause noninfectious disease.

PROCESSES OF DISEASE The system responsible for protecting the

body from disease is called the immune system and has 3 general lines of defense:

First line is the skin which acts as a barrier The second line is when cells are injured,

blood flow to that area increases bringing white blood cells in to attack the pathogens. One type is a macrophage that engulfs and kills pathogens

The third line involves killing specific pathogens and this involves white blood cells called T cells and B cells

PROCESSES OF DISEASE In 1928, Alexander Fleming accidently

discovered that certain fungus secreted a substance that could inhibit the growth of bacteria

This substance, penicillin, become one of the first antibiotics. Antibiotics kill bacteria without killing human cells

Antiviral drugs are used to inhibit a virus’s ability to invade and multiply inside living cells because antibiotics don’t work on them

REVIEW1) How are pathogens related to human

health?a. They act as a barrier for the bodyb. They causes diseasec. They produce blood cellsd. They drain nutrients from the body

REVIEW1) Which phrase describes an infectious

disease?a. Causes death when it is contractedb. Is inherited from parents by offspringc. Can be spread from one person to anotherd. Does not evoke an immune response

REVIEW1) How do macrophages help protect the

body from disease?a. They produce white blood cellsb. They engulf and kill pathogensc. The produce T and B cellsd. They prevent pathogens from entering the

body

REVIEW1) Which of the following causes

botulism?a. A toxinb. A mineralc. A mutationd. A nutrient

NATURAL SELECTION Evolution is defined as change in a

population over time Darwin was among the first to recognize

the importance of diversity within a population and its role in evolution

His theory of natural selection or survival of the fittest accounts for an increase in the proportion of individuals with advantageous characteristics within a species, it also accounts for extinction.

NATURAL SELECTION Darwin observed that organisms thrive

in the environments they are best suited for.

Although the members of a species share many characteristics, there will be variation among them.

With the exception of identical twins, members of a species produced as a result of sexual reproduction are genetically unique (genetic diversity).

One way genetic variation is increased is through mutations.

NATURAL SELECTION Most mutations have no effect, some

are beneficial as well. Individuals compete for resources (food,

mates, and space), if an organism’s characteristics are beneficial giving it an advantage, it will more likely survive and pass on its genetic information (natural selection).

In other words, nature “selects” such organisms for survival.

We call these traits adaptations.

NATURAL SELECTION Darwin’s ideas in “On the Origin of

Species”Variation exists in populationsOrganisms compete for limited resourcesOrganisms produce more offspring than can

survive Individuals with variations suitable for

environment survive and reproduce

NATURAL SELECTION Darwin studied tortoises, among many other

species, and observed that the shells of various land tortoises differed depending on which island they inhabited. Some in wet areas had dome-shaped shells and shorter necks while those on dryer islands had curved shells and had long necks (both adapted to its environment)

Darwin speculated that in the past, a single species of tortoise inhabited these islands, but as the conditions changed, those best suited survived, pass on genetics, and reproduced creating differences

NATURAL SELECTION Extinction: sometimes genetic differences

are not enough to help a species survive, and the species become extinct. This is the death of all individuals within a species

There have been 5 major periods of extinctions during Earth’s history and sea-level changes related to global warming and cooling are linked to each one

Today, many scientists think we are on the brink of a 6th major extinction due to human activity

REVIEW1) Which of the following best characterizes

natural selection?a. Faced with an environment in which leaves grew

only at the tops of most relatively short trees, giraffes responded by growing long necks

b. Only giraffes with long necks moved into an environment in which leaves grew only at the tops of relatively short trees

c. During their lifetimes, short-necked giraffes grew long necks so they could reach leaves at the tops of relatively short trees

d. Among a population of giraffes, those with long necks were able to survive better in an environment in which leaves grew only at the tops of most relatively short trees

REVIEW1) Some plants in the desert, like cacti,

have long roots and thick stems so they can obtain and store water. What do we call these characteristics that increase a cactus’s chance to survive in the desert?

a. Adaptationsb. fossilsc. speciationd. mutations

REVIEW1) Which of the following best describes

the main concept behind Darwin’s theory of natural selection?

a. Organisms compete for limited resourcesb. Organisms best suited to their

environment will survive and reproducec. Organisms vary in their physical traits,

and some traits are inheritabled. Organisms produce more offspring than

can survive

REVIEW1) Which of these is used to describe the

death of all individuals within a species?

a. isolationb. evaporationc. speciationd. extinction

SPECIATION A species is a group of organisms that

can produce viable offspring. There are more than 2 million species that

have been identified and millions more that are not yet discovered. How did so many evolve? What causes a new species to evolve from earlier ones?

Speciation is the evolutionary process by which new species form.

This occurs in three basic ways: geographic isolation, parapatric speciation, and behavioral isolation

SPECIATION Geographic isolation (allopatric

speciation): when a population is separated into 2 geographically isolated populations by a barrier that can no longer breed with each other (can reach each other). Natural selection occurs on either side and populations become genetically different from each other and can no longer interbreed.

SPECIATION Parapatric speciation: occurs when

two populations live in different environments next to each other…one may be hot and the other wet, natural selection favors different adaptations causing these populations to become genetically different.

Individuals between the 2 populations interbreed causing a hybrid zone. They are less fit and don’t survive and we get 2 new species.

SPECIATION Behavioral isolation: individuals

within a population may have different courtship rituals or other types of behaviors. Differences in behavior, such as mating at different times of the year, cause the individuals to choose different mates causing them to become genetically different and hence two species coexist.

REVIEW1) What happens during the process of

speciation?a. A species becomes genetically diverseb. Two species become onec. A species becomes extinctd. A new species is formed

REVIEW1) Two neighboring populations become

genetically different. Individuals at the boundary between the two populations interbreed and form a hybrid zone. The hybrid offspring have low fitness and are not able to survive and reproduce. Which type of speciation is this describing?

a. Geographic isolationb. Parapatric speciationc. Behavioral isolationd. migration

REVIEW1) Suppose a dam breaks and water

forms a river that splits a population of squirrels. Half the population is on the eastern side of the river, and the other on the western side. After 500 years, squirrels coexist again but are not able to interbreed. What type of speciation does this represent?

a. Geographic isolationb. Parapatric speciationc. Behavioral isolationd. Migration

DNA DNA is a macromolecule found in the cell’s

nucleus that dictates the identity and functions of the cell.

DNA is made up of nucleotides Nucleotides are made up of phosphate, a

sugar, and a base. 4 different nitrogenous bases: adenine (A),

thymine (T), guanine (G) and cytosine (C) Rosalind Franklin and James Watson and

Francis Crick discovered the double helix shape

DNA The fact that A always pairs with T and

C always pairs with G is called Chargaff’s rule

One strand of DNA is complementary to the other

DNA replication is the copying of DNA before a cell divides.

DNA is unzipped and each strand acts as a template for a new strand. From this we get 2 new DNA molecules with one old and one new strand….they are exact copies of the original

REVIEW1) What are the building blocks of DNA?

a. Genes b. Nucleotides c. Amino acidsd. Ribosomes

REVIEW1) Which of the following nucleotides

bonds with cytosine?a. Guanine onlyb. Cytosine and guaninec. Adenine onlyd. Adenine and thymine

REVIEW1) What is the result of DNA replication?

a. More traits are added to a living organism as it ages

b. Increased space is filled within the nucleus of a growing cell

c. The traits of a living organism are changed to meet its needs in a new environment

d. Cells produced through cell division are provided with a complete copy of genetic material

REVIEW1) If one strand of the DNA molecule

reads ATGCCGT, what would the complementary strand read?

a. TACGCCUb. UACGGCAc. TACGGCAd. TAGCCGA

RNA AND PROTEIN SYNTHESIS DNA contains the genetic codes that are

used to make RNA. In turn, RNA codes for the sequence of amino acids used to make proteins.

RNA, ribonucleic acid, is similar to DNA. It is single stranded, has uracil (U) instead of thymine, and has the sugar ribose instead of deoxyribose.

3 types: mRNA, tRNA, and rRNA

RNA AND PROTEIN SYNTHESIS The information in DNA is used to make

proteins. Recall that traits, like hair color and eye color, are determined by proteins. Proteins are chains of amino acids (there are 20) and their arrangement determines its shape and function.

Proteins are made on ribosomes. DNA does NOT leave the nucleus, so RNA serves as a messenger.

RNA AND PROTEIN SYNTHESIS Transcription: The DNA code is put into a

message in the form of messenger RNA (mRNA).

The instructions in mRNA are arranged as sequences of three nucleotides known as codons. Each codon codes for a particular amino acid or marks the beginning or end of a process.

When transcription occurs, the mRNA’s code will match up with the DNA, but use uracil instead.

RNA AND PROTEIN SYNTHESIS Translation: the instructions are decoded

and used to arrange amino acids in a protein chain. It involves tRNA which carries the amino acids to the ribosome where the mRNA is matched up and ready to make a protein.

Ribosomal RNA or rRNA along with proteins make up the ribosome.

The entire process of building a protein is called protein synthesis (transcription + translation)

REVIEW1) Which is the best meaning for the term

transcription?a. Joining togetherb. Writing outc. Changing from one language to anotherd. erasing

REVIEW1) An mRNA strand has the following

sequence of bases: AGUACA. What was the base sequence of the matching DNA strand?

a. UCAUGUb. AGTACAc. AGUACAd. TCATGT

REVIEW1) Where does transcription occur?

a. Cell membraneb. Cytoplasmc. Nucleusd. ribosome

REVIEW1) The sequence of mRNA is AGUACA.

What is the sequence of tRNA?a. UCAUGUb. AGTACAc. AGUACAd. TCATGT

GENETIC ALTERATIONS Mutations: changes in the sequence of

nitrogenous bases in DNA Two types: gene mutations and

chromosomal mutations Can have no effect, a positive effect, or

a negative effect Point mutation: a mutation involving a

change in a single base Frameshift mutation: where a base is

added or deleted so the entire gene would be affected

GENETIC ALTERATIONS The consequences of DNA mutations

depend also on the type of cell in which the mutations occurs. If in somatic cells (body cells) it will affect the individual only, if in gametes (sex cells) it can be passed on to the offspring

Chromosomal mutations: involve in an entire chromosome.

Sometimes this happens when chromosomes fail to separate during meiosis (making sex cells) and this is called nondisjunction.

GENETIC ALTERATIONS Four types of mutations result from changes

to the structure of a chromosome: deletion, inversion, translocation, and duplication.

Deletion: part of chromosome breaks off Inversion: section of chromosome breaks off

and changes location in the same chromosome

Translocation: piece of a broken chromosome combines with a different chromosome

Duplication: a section of chromosome is repeated

REVIEWA-G-C-A-T-T-A-C-G A--C-A-T-T-A-C-GT-C-G-T-A-A-T-G-C T--G-T-A-A-T-G-C1) The diagram above shows a strand of

DNA before and after it was mutated. What type of mutation does the DNA sequence show?

a. Frameshiftb. Deletionc. Inversiond. translocation

REVIEW1) Which of these statement(s) is/are

true?I. Mutations always have a negative

effectII. Mutations can have a positive effectIII. Mutations can have no effectIV. Mutations usually have a negative

effecta. I onlyb. I and III onlyc. II, III, and IV onlyd. I, II, III, and IV

REVIEW A-B-C-D E-F-G A-B-C-D E-F-E-F-G

1) The picture above shows an example of a chromosomal mutation. What type is it?

a. Deletion b. Inversion c. translocationd. duplication

REVIEW1) Mutations that occur in gametesa. Are no different from those that occur

in somatic cellsb. Are not passed down to offspringc. Are always caused by random events

in natured. Are passed down to offspring

ADVANCES IN GENETICS Biotechnology is the use of organisms or

their products to improve human health and food production

Selective breeding is the process in which only those individuals with desired traits are selected to reproduce and thus pass their favorable traits to the next generation

Hybridization is crossing dissimilar individuals

ADVANCES IN GENETICS Genetic engineering is a way that genes

or pieces of DNA are taken from one organism and transferred to another

Genetic engineering is usually done with recombinant DNA, joining together two different pieces of DNA

Typically scientists will transfer more complicated DNA (like from human) into a simple one like a plasmid from a bacteria.

A plasmid is a simple circular chromosome

ADVANCES IN GENETICS Transgenic plants and animals are

organisms that carry foreign genes inserted into their genome.

Genetically modified food is made to make it more disease-resistant, or to have more vitamins or antibiotics in them

Genetically modified domesticated animals are made to produce more or help disease (like wool in sheep or insulin in cows)

ADVANCES IN GENETICS Cloning is where identical individuals are

created from a single cell. A donor nucleus is transferred into the egg of another and then implanted into a foster mother

DNA fingerprinting is the specific pattern an individual’s DNA makes when run with gel electrophoresis

In electrophoresis, the DNA pieces (cut by an enzyme) travel according to size and charge and is very specific to each person. It is used for paternity and to solve crimes

ADVANCES IN GENETICS Human genome project identified all

genes in human DNA. It took 15 years and was worked on by scientists from all over the world

REVIEWIn order for cloning