Biological Principles for Non-Majors EXAM 2 (Mods 4-6)

Two types of nucleic acids

DNA and RNA

What is a polymer?

a large molecule made by repeating a smaller unit

What makes up nucleic acids?

nucleotides

What makes up proteins?

amino acids

Gene

A segment of DNA on a chromosome that codes for a specific trait

What does RNA do?

transfers genetic information from DNA to ribosome for protein synthesis

What is DNAs role in protein synthesis?

"DNA makes RNA, and RNA makes proteins"

Transcription

in the nucleus, information in a DNA gene is converted to an RNA molecule

Translation

in the cytoplasm, the RNA message is converted to protein

What is the unique base-pair in mRNA?

Uracil (U) replaces Thymine (T) and pairs with Adenine (A)

Codons

sequences of three nucleotides, each of which specifies one amino acid

What are tRNAs?

translates RNA language to protein language with the help of an anticodon

Triplet code

correspondence between an mRNA codon and its amino acid

Start codon

AUG

Stop codons

UAA, UAG, UGA

Biotechnology

the manipulation of organisms or their components to make useful products

DNA technology

a set of methods for studying and manipulating genetic material

Genetic engineering

the direct manipulation of genes for practical purposes

DNA cloning

producing multiple identical copies of a piece of DNA

Plasmid

A small ring of DNA that carries genes

Restriction site

Specific DNA sequence recognized by a restriction enzyme to cut

Restriction enzymes

proteins that cut DNA only at specific nucleotide sequences

Restriction fragments

Fragments of DNA that result from the cuts made by restriction enzymes

Sticky ends

Single-stranded ends of DNA left after cutting with enzymes (ends of restriction fragments)

DNA ligase

enzyme that pastes two DNA fragments together

Recombinant plasmid

a plasmid with foreign DNA inserted into it

Recombinant DNA

a segment of DNA containing sequences from two different sources

Genetically Modified Organisms (GMOs)

organisms that have acquired one or more genes by artificial means

Transgenic organism

an organism that contains genes from another species (ex. goat carrying a human gene)

4 pros to GMOs

1. No scientific evidence that GMOs harm humans or environment

2. Safety measures in place

3. Can be more nutritious and grow in a wider variety of habitats compared to standard crops

4. Strains of microorganisms are genetically crippled

4 cons to GMOs

1. May be harmful to humans or the environment in ways we don't know

2. GMOs might escape into the environment and pass on genes to wild organisms

3. Possible loss of diversity

4. No labeling standard for GMOs (unaware consumers)

What is a major similarity in the production of GM plants and mammals?

Both use a plasmid to introduce foreign DNA

Natural Selection

Individuals with traits that make them better-suited to compete for available resources/environment will survive/have more offspring

Evolution

The gradual change in a species over time (continuous natural selection)

Adaptation

inherited characteristic that increases an organism's chance of survival --OR-- accumulation of favorable traits in a population over time

Antibiotics

natural or synthetic drugs that inhibit or kill bacteria (ex. penicillin)

Artificial Selection

selective breeding of domesticated crops and animals

Why is the domestication of animals considered "artificial" selection?

Because humans, rather than the environment, decide the reproductive success

1. Most abundant GMO food?

2. First GMO animal approved for human consumption?

1. Bt corn (80%)

2. AquAdvantage salmon

How is human insulin produced, and why?

HOW: DNA cloning process

1. Isolate human gene for insulin

2. Get plasmid from a bacterium

3. Insert human gene into bacterium DNA

4. Insert recombinant DNA into a bacterial cell

5. Grow bacteria with human insulin gene

6. Isolate and extract insulin

WHY?: Needed for people with T1 Diabetes (insulin injections)

What in Bt corn has been modified, and why?

Pesticide gene from the bacterium Bacillus thuringiensis produces a protein toxic to insects

What in GloFish has been modified?

single fluorescent gene from jellyfish introduced to the fish

What in AquAdvantage salmon has been modified?

Growth gene combo from a Pacific salmon and a gene regulator from a cold-water fish. Causes salmon to grow year-round and get bigger.

Emerging infectious disease (EID)

a contagious disease that is rapidly increasing in number of cases

Zoonotic disease

disease passed from an animal to a human (75% make up EIDs)

ex. rabies

Spillover event

When an infectious disease that normally infects one species spreads to a new species

Reservoir host

Preferred animals/hosts that viruses live and reproduce in

Direct contact

Coming into direct contact with saliva, blood, urine, feces, mucous, or other bodily fluids, of an infected animal

(ex. rabies)

Indirect contact

Coming into contact with areas or surfaces where infected animals have been, such as chicken coups, barns, or soil

(ex. Lassa fever)

Dead end/incidental host

virus can't be transmitted from one human to another--OR-- the host the virus is stuck in, unable to spread

Epidemic

an unexpected increase in the # of disease cases in a specific region; "outbreak"

Pandemic

An epidemic with an exponential growth in cases and is geographically widespread (skyrockets)

Endemic

A disease that's consistently present but limited to a specific area; generally predictable

Infectious disease

A disease that is caused by a pathogen and that can be spread from one individual to another.

Virulent

refers to pathogen's ability to harm host

How do land use changes affect the emergence and/or spread of infectious diseases?

destruction of habitats --> Increased interactions with wildlife increase the chances of zoonotic disease emergence

How does food production affect the emergence and/or spread of infectious diseases?

animals crowded together, provides a perfect environment for rapid disease spread, viral mutations, and spillover to farm workers

How does wildlife trade affect the emergence and/or spread of infectious diseases?

wildlife can interact with new animal species and humans, increasing the chances for viral mutations and spillover events

How does climate change affect the emergence and/or spread of infectious diseases?

As the planet warms, disease vectors like ticks and mosquitoes are able to survive and transmit disease

How does travel and transportation affect the emergence and/or spread of infectious diseases?

People, wildlife, food, and disease vectors can all be moved about the planet easily and quickly, increasing the potential for disease emergence and disease spread

Bacteria

single-celled organisms that lack a nucleus; prokaryotes

Protist

all eukaryotes that do not belong to the plant, animal, or fungus kingdoms

Protozoans

protists that obtain nutrients primarily by eating

Amoebas

single-celled protists with great flexibility in their body form

Slime molds

protists that resemble fungi in appearance and lifestyle.

Algae

photosynthetic protists able to produce their own food from sunlight

Seaweeds

large, multicellular marine algae that grow on rocky shores and in shallow marine habitats

Two defining characteristics of life

1. Must grow

2. Can reproduce on its own

Virus

A tiny, nonliving particle that invades and then reproduces inside a living cell.

What is a virus made up of?

Nucleic acid, capsid, and recognition spike(s)

Capsid

"genes in a box": nucleic acid (either DNA or RNA) wrapped in a protein container

Nucleic acids in viruses

DNA or RNA, single- or double-stranded

(living cells always use double stranded)

Recognition spike

a protein structure that sticks out from the surface of a virus

How does a virus reproduce?

Attaches to a host cell, enters, and inserts its genetic material. It then directs the host to produce more viruses until the host cell ruptures, spreading to other healthy cells.

Bacteriophage

A virus that infects bacteria

Virus examples

Influenza, Herpes, Measles, Tobacco mosaic

Pathogen

A microorganism that causes disease

What types of organisms can be pathogens?

bacteria, fungi, protists (alive), viruses (not-alive)

Prion

infectious protein; misshapen versions of normal brain proteins; incurable and fatal

Viroids

small, circular single-stranded RNA molecules that cause disease in plants

Strain

A variant with distinct characteristics compared to the original

Variant

A virus with a mutation

How might mutations affect a virus?

Mutations can alter viruses into deadlier or more contagious variants

If a virus mutates faster or more frequently, how might this affect the behavior of the virus or how it spreads through a population?

Viruses that mutate frequently generate new genetic variants at a high rate. Frequent mutations, combined with contact between populations and hosts, can make a virus spread rapidly

COVID-19 (CoronaVirus Disease 2019)

a contagious disease caused by virus SARS-CoV-2* (*Severe acute respiratory syndrome coronavirus 2)

Symptoms of COVID-19

flu-like symptoms including fever, cough, headache, fatigue, shortness of breath, and loss of smell and taste

(1 in 6 ppl develop severe versions)

Prevention of COVID-19

hand washing, masks/shields, avoiding large gatherings, social distancing, increasing ventilation, vaccines

What factors increase risk of infection?

crowding, time, and poor ventilation

Vaccine

substance prepared from killed or weakened pathogens and introduced into a body to produce immunity

First successful vaccine

Smallpox vaccine

Inoculation

introducing a pathogen to an organism to elicit disease/ immune response

Vaccination

introducing a vaccine to stimulate the immune system and production of memory cells

(aka immunization)

Difference between Inoculation and Vaccination?

Inoculation introduces a pathogen (Broader/umbrella term)

Vaccination introduces a formulated vaccine

A person is infected when

a virus enters a person and takes up residence

antibodies

small proteins that bind to surface molecules of pathogens and kill them, or prevent them from infecting cells and replicating, or flag them for destruction

antigen

a molecule that elicits an immune response

Memory response

second more effective immune response

Booster

A repeat vaccine to boost protection

Lymphatic system

helps remove toxins and pathogens from the blood and interstitial fluid

Lymphocytes

white blood cells that reside in the lymphatic system (T + B cells)