bio exam 3

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Primary structure

* unique and specific amino acid sequence encoded in DNA


* the amino acid sequence providers specificity in function and folding conformation

Steriods

cholesterol, estrogens and testosterone

What are trans fats?

partially hydrogen oils, naturally unsaturated fatty acids tails have been chemically altered to be more saturated by adding H atoms

Trans fats are

Unhealthy: can lead to cardiovascular disease, reduced membrane integrity, free radical damage; can destroy molecules

Fats

Stearic acid: saturated fat and fatty acids

Oils

very kinky; lipids that are liquid at room temperature

Lipids

found in artificial foods, found in nature; avocados

Carbohydrates Functions

* energy source: glucose is metabolized


* energy storage: starch and glycogen


* structural support: cellulose, chitin, cartilage
* structural support: cellulose, chitin, cartilage
* transport of energy source: sucrose (plant) and lactose (milk)

Chitin structure / function

is found on the surface of bugs/insects, give structural surface and many surgical thread is made this

Polysaccharides

are chains of monosaccharides, consists of small organic (monomer) sugars

Disaccharides

are double sugars that consist of 2 monosaccharides, joined by a chemical bond reaction

Monosaccharides

simples, ribose (RNA), deoxyribose, glucose; starch, cellulose, glycogen

Principle Types of Biological Molecules

carbohydrates, lipids, proteins, nucleic acids

Hydrolysis

breaking (assimilating) it down into it's components

Dehydration Synthesis

= condensation reaction (waterless)

Why are functional groups important?

each group imparts specific chemical properties

Functional groups

* hydrogen, hydroxyl, carboxyl, carbonyl (aldehydes & ketones)
* amino, sulfhydryl, phosphate, methyl & acetyl

Primary Structure

unique and specific amino acids sequence encoded in DNA, the amino acid sequence provides specificity in function and folding conformation

Secondary Structure

H bond forms between -C=O & -N-H of two peptide bonds, H bonds do not involve R groups, regular repeating units, contributes to structure (strong)

Tertiary Strcutre

consists of irregular contortions due to interactions between various side chains of amino acids, interactions between different R groups

Quaternary Structure

A whole bunch of different groups, shape of a complex aggregate protein, that is attributed to the three-dimensional arrangement of its subunits

Nucleotide

is the monomer of nucleic acids, it consists of a phosphate groups, a pentose sugar and a nitrogenous

Double Helix

nitrogenous bases point to the centre of the double helix, sugar-phosphate backbone is on the ouside

Cells

enclosed by a plasma membrane, need a genetic blueprint to tell them what to do, contain cytoplasm

Prokaryotic cells

developed pretty early, do not have a nucleus or other membrane-bound organelles

Eukaryotic cell

more complex, possess a membrane enclosed nucleus, probably arose from prokaryotic

Cytoskeleton

provides shape and movement

Nucleus

is surrounded by a nuclear envelop, contains chromosomes which carry the cell's genetic information, contains the nucleolus which is the site of rRNA synthesis and ribosome assembly

Nuclear envelope

controls passage of materials into and out of the nucleus, is a double membrane

Ribosomes

consists of small and large subunits, are involved in protein synthesis

Why is the plasma membrane important?

it isolates the cell and may help it interact with its environment

Golgi apparatus

sorts chemically alters & packages important molecules

Vacuoles

found in the fungi and plants, occupy a large portion inside the cell, serves are storage depots for water, ions and proteins

Membranes

separate living entities from non living entities, allow cell's internal content to be different from the external environment

What are the functions served by the plasma membrane?

bilayer, serves as a boundary, selective barrier

Phospholipids

spontaneously form bilayers in water

what are the NONPOLAR regions?

hydrophobic fatty acids and tails: water fearing

What are POLAR regions?

hydrophilic heads: water loving

Diffusion

spontaneous, passive

Glycoproteins

is a protein that has carbohydrates in it, allows the cell to interact with other cells and is apart of the membrane

DNA is the

hereditary blueprint

Endoplasmic reticulum: rough

is studded with ribosomes & site proteins are made

Endoplasmic reticulum: smooth

has no ribosomes & make phospholipids and cholesterol

How are proteins secreted?

secretory protein is manufactured on ribosomes of the rough ER

Osmosis

passive, dealing with the transport of water: water diffuses from a less concentrated solution (hypotonic) to a more concentrated solution (hypertonic)

Hypotonic

lower solute concentration then that in the cell

Hypertonic

concentrated solution, greater solute concentration than in the cell

Isotonic

equal solute concentration compared to that in the cell

What happens when plant cells are placed in different solutions: hypotonic

becomes turgid

What happens when plant cells are placed in different solutions: hypertonic

plsmolyzed

What happens when plant cells are placed in different solutions: isotonic

flaccid

What happens when animal cells are placed in different solutions: hypotonic

animal cell swells or bursts or lyses

What happens when animal cells are placed in different solutions: hypertonic

animal cell shrivels or crenates

What happens when animal cells are placed in different solutions: isotonic

equal movement of water in and out of animal cell

Facilitated Diffusion

is a form of passive transport, is assisted by a specific transport protein

Exocytosis and example

* exports macromolecules out of a cell
* crying: tear glands export salty solutions containing proteins

Endocytosis

the process of importing macromolecules into a cell

Phagcotysis

a lot to do with feeding

Huntington's disease

Lethal deterioration of nervous system phenotypic effects appear at a later age after the individual ay have transmitted lethal allele to children

Turner syndrome X0

Female, one viable human monosomy: has one sex chromosome, short stature, webbed neck, shield like chest & internal sex organs do not mature; difficult making eggs

Triple X syndrom: Trisomy X (XXX)

Female, usually normal phenotype, fertile

Klinefelter Syndrome (XXY)

Male, very small tests, sterile, display feminine body contours (bigger boobs), have normal intelligence

Jacob Syndrome (XYY)

Male, much taller compared to the average male, normal fertility and intelligence

What can abnormal numbers of autosomes cause?

Down syndrome

What are the three components of each nucleotide?

phosphate group, deoxyribose sugar & nitrogen containing base

How does DNA encode information?

information is encoded in the order of nucleotides, information depends on the sequence of nucleotides; not their number

Why is DNA replication so important?

replication of hereditary information is very important since the DNA programs assists int he regulation & control of all biochemical, anatomical & physiological traits

What are the major enzymes that are involved in DNA replication?

DNA helicase, DNA polymerase & DNA ligase

mRNA

message carries the code for a protein from the nucleus to the cytoplasm

tRNA

transfer RNA: molecule transport amino acids to site the ribosomes

rRNA

ribosomal RNA: proteins from ribosomes

how is the information encoded in the DNA utilized in a cell?

majority of genes contains information for the synthesis of proteins

Codon

is the basic unit of the genetic code

Dictionary of the genetic code

64 codons, 61 triplets code for amino acids

three stop codons

UAA, UAG, UGA

Initiation

of transcription starts when RNA polymerase binds to the promoter of a gene

Elongation

generates a growing strand of RNA

Termination

of transcription occurs when RNA polymerase reaches the termination signal

Point mutations

a mutation restricted to one or a few base pairs in a single gene

Mutation

a change in the genetic material of a cell, a mutation is a change in an organism's DNA

Base pair substitutions

nucleotide and its partner are reaplced with another paur of nucleotides according to base-pairing rules

Base pair insertions

the insertions of one or more nucleotides pair into a gene

Essentialism

Plato: an ideal world, illusionary world, perceived by the senses: smell, hearing, vision

Natural Theology

Paley: discovery of the creators (god's plan) through study of nature

Linneus

Developed taxonomy (classification hierarchy for naming organisms)

Gradual geological change

Hutton: profound change is the cumulative product of slow continuous processes

Inheritance of Acquired Characteristics

Lamarck: inheritance of acquired characteristics, use of disuse of body parts lead to their development or their deterioration

Catashtrophism

Cuvier: differences between older and modern forms, earth's history is marked by local catastrophic events, not from gradual processes of change

What is an example of catastrophism?

Floods and droughts led to extinctions

Fossil record

there is a gradual transition with the layers of sediment with respect to the depth of the sediments, there is a relationship between the sediment layers and the fossils present in those layers & older fossils are found in the deep sediments whereas the more recent fossils are found in the sediments in the upper layers

Uniformitarianism

Lyell: geological processes have constant (uniform) rates, which balance out over time & earth is very old

Charles Darwin

1859 publishes "On the Origin of Species by means of Natural Selection"; the theory of evolution suggests that all organisms on earth are related by common ancestry and have changed over time, primarily by natural selection & evolutionary processes have changed life on earth from early beginnings to the present diversity of organisms

What was Charles darwin's theory considered?

Radical; since it went against prevailing scientific and world views held for centuries HOWEVER most biologists accepted the idea of evolution

Natural Selection

Mechanism --\> small changes that increase survival and reproduction

Darwin and Wallace's Theory rests on four postulates

1. Individuals in a population vary
2. traits are passed from parent to offspring
3. some individuals fail to survive and reproduce
4. survival and reproduction are not determined by chance

Differential reproductive sucess

those with genetic traits best suited to their environment will generally leave disproportionately large numbers of surviving/fertile (large representation) displaying those traits in the future generations

Darwin's 2 claims

1. modern species evolved from ancestral forms
2. mechanism of evolution is natural selection

Why did Darwin have great difficulty convincing that natural selection was the mechanism of evolution?

There was no detailed knowledge/material of genetics and the chromosomal basis of inheritance

Descent with modification

Darwin viewed all organisms as being related through descent from a common ancestor

Structural Homologies

Homologous structures provide evidence of common ancestry