Unit 2- Unity And Diversity Of Life Flashcards
4 Special Properties of Water
Cohesion and Adhesion
High SHC
Water Expands as it Freezes
Water is a really good Solvent
Water Bond
- oxygen in the water molecules hogs the shared electrons
- causes a partial negative charge on oxygen and partial positive charge on hydrogen
- polar molecule
- causes water to stick to itself through hydrogen bonds
Cohesion and Adhesion
Cohesion- water sticks to water
Adhesion- water sticks to other things
*allows plants to move water up their stems
High Specific Heat Capacity
SHC- how much heat has to be put into a substance to make it’s temperature go up
- water heats up slowly an cools down slowly due to hydrogen bonds holding the molecules back
- bungee cord running example
How does SHC of water effect life?
1) causes oceans to cool to planet
2) makes water a good insulator for our bodies
3) sweating cools our bodies for this reason
Water Expands as it Freezes
- water is densest at 4C
- when water loses lots of energy, the molecules cannot overcome their attractions to their neighbours on either side and become evenly spaced
- ensures lakes don’t freeze solid
- allows for spring and fall turnover to bring O2 down for aquatic life
Solvent and solute
Solvent- something that something is dissolved it
Solute- the thing that is dissolved
- when something is dissolved, each atom of the solute is completely surrounded by molecules of the solvent
Water is a really good solvent
- the charges on water are attracted to the charges on a solute
- provides a medium for all the chemical reactions which maintain/sustain life
- water can hold the most dissolved things
- blood is mostly water- carries nutrients and other things needed for life
- holds dissolved gases for aquatic life
Polar
Molecule with differently charged regions
- mixes with other polar things
- polar=hydrophilic
Non-Polar
Molecules that don’t have differently charged regions
- mixes with other non- polar things
- non-polar= hydrophobic
Organic molecules
-Carbon based molecules that form living things (CO2 is the exception)
-carbon can bid to up to 4 other things, allowing it to form huge complicated structures
-contain: (CHONPS)
C,H always
O,N often
P,S sometimes
Macromolecules
Big Molecules
Polymers
A molecule made of a whole bunch of similar small molecules joined together Carbohydrates Lipids Proteins Nucleic Acids
Monomers
Similar small molecules that form polymers Monosaccharides Fatty Acids Amino Acids Nucleotides
Carbohydrates
Literally carbon and water
(CH2O)n
Made of monosaccharides
Monosaccharides
Glucose-hexagon, less sweet, metabolizes quickly
Fructose- pentagon, really sweet, found in fruit
Ribose- also a pentagon
Disaccharides
Sucrose-glucose and fructose
Maltose- glucose and glucose, produced when plants start to grow
Lactose- glucose and galactose
Dehydration synthesis
How monosaccharides join together
-OH groups are very reactive; join together with another OH to make water and leaving behind one O which joins them together
Hydrolysis
How monosaccharides get separated
-add water which creates the two separate OH groups
Functions of carbohydrates in humans
1) Fibre- made of cellulose which we can’t digest- flows out of the body
2) storage of glucose in the form of glycogen (basically starch with branches all over the place)
Glycogen Cycle
Normal blood sugar-eat a meal-pancreas increases insulin-sugar stores as glycogen in liver and muscles- normal blood sugar- been a while since a meal- blood sugar drops-pancreas produces glucagon-liver and muscles break down glycogen to release glucose-normal blood sugar
Function of carbohydrates in plants
1) use starch to store glucose- starch is a big long chain of glucose
2) cell walls made of cellulose- long chain of glucose but every other glucose is upside down
Function of carbohydrates in fungi and insects
1) convert glucose into a similar molecule, which chains together to form chitin
2) chitin forms the cell walls of fungi and exoskeleton of insects
Function of carbohydrates in bacteria
1) cell walls made of peptidoglycan which is chains of chitin connected by amino acids chains (really strong)
* penecillan breaks apart the amino acids, causing the cell wall to fall apart
Uses of Lipids
- long term energy storage- stores more energy per molecule than carbs
- insulation
- protection/cushioning
- forming cell membranes
Structure of Fat
Glycerol backbone plus fatty acid chains
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Mono, di, and triglycerides
Mono- one fatty acid chain
Di- two fatty acid chains
Tri- three fatty acid chains
*all non-polar, all saturated fats
Unsaturated Fats
- have double bonds in the fatty acid chain
- puts a kink/bend in the chain
- takes up more space, so they tend to be liquid at room temp
- saturated fats take up less space (no kinks) so they tend to be solid at room temperature
Cis Fats
-unsaturated fat
-carbons are on the same side of the double bond
C C
/. . /
C. C=C
-Cis double bonds kink the chain, making the carbons on the same side
Trans fats
- type of unsaturated fat
- double bonds don’t kink the chain- the carbons are on opposite sides of the chain
- not found in nature
- only produced through hydrogenation- put cis fats and hydrogen under pressure which breaks some of the double bonds, but makes the rest into trans
- found in things that say hydrogenated or partially hydrogenated vegetable oil
Phospholipids
- fat which has 2 fatty acids (non-polar) and one phosphate group (polar)
- allows water (polar) and fats (non-polar) to mix
- forms all cell membranes by making a double layer with the tails in
- keeps things in and out
Membrane Permiability
What gets through -small, uncharged particles (water, gas) -move by diffusion (movement of particles from areas of high concentration to low concentration) -non-polar molecules (steroids) What can't get through -large or charged molecules
Fluid mosaic
- cell membrane is a fluid membrane
- flows (particles move past each other) and made if lots if different things
- cell membrane is a fluid; phospholipids move around like the surface of a bubble
- cell membrane is made up of proteins, cholesterol and other things
Endocytosis
- a cell accepting things into it
- phago and pino cytosis
Pinocytosis
-the cell wants a particle, so it makes a little dip in the membrane to fit the particle, then it folds around, trapping the particle in a vesicle
Phagocytosis
-the cell reaches out, makes a loop of cell membrane around the particle, and pulls the arm back into the cell, leaving the particle in a vesicle
Exocytosis
-cell traps a particle in a vesicle, which joins with the cell membrane, which then moves away on the outside, pushing the particle out
Proteins
Do everything
Monomers are amino acids
Jobs of a Protein
1) messengers and receptors
2) help fight disease
3) transport materials in/out of cells
4) form structures of bones, skin, hair, nails, teeth
5) enzymes
Messengers and Receptors
Proteins form the messenger molecules and the receptors which tell the cell to die, divide, or metabolize
Proteins fighting bacteria
White blood cells (phagocytic leukocytes) have proteins which stick to proteins on bacteria and engulf the bacteria
Protein fighting viruses
Antibodies- proteins that stick to viral proteins and act as a flag
-the virus either kills the cell after making the cell reproduce more viruses or the cell is killed by a cytotoxic T-cell
Facilitated diffusion
when materials diffuse through a protein channel; different channels for different proteins; takes no energy because things move from areas of high concentration to low concentration
Active Transport
Protein pumps force materials to go from areas of low concentration to areas of high concentration (where it doesn’t want to go) using energy
Collagen
Protein
Fibrous, strong, elastic
Gives bones some bendiness
Allows skin to stretch
Enzymes
Biological catalysts- they help reactions to happen
1) some help hydrolysis happen- lactase, maltase
2) some help dehydration synthesis- DNA polymerase
3) some help with metabolism/energy production ATP synthase
Amino Acids
H H. O
. |. //
N - C - C
/. |. \
H. R. OH
-20 different R groups=20 different amino acids
-different amino acids chained together in different ways determines the function of the protein
Attractions between amino acids
Charges attract (+/-) and repel (+/+,-/-)
Polarity- polar attracts to polar, non polar to non polar
*cause the protein to fold in different ways
Protein Conformation
The final folded shape of a protein
- can reversably change (allows a receptor which received a messenger to change shape to send a message to the inside of the cell)
- one sequence of amino acids will always fold in the same conformation
Denatured proteins
In extreme heat or PH, proteins denature, or change conformation permanently
Nucleic Acids
Form our genetic material (contains instructions)
- contain protein- making instructions
- proteins make us who we are
- our differences come in tiny tweaks to the overall protein-making instructions
- we pass these protein makin instructions to our kids
Nucleotides
Made of a phosphate, a 5 sided sugar (ribose of deoxyribose) and a nitrogenous base
Adenine, Thymine (DNA), Cytosine, Guanine, Uracit (DNA)
Nucleotide Joining
-join in chains by dehydration synthesis
-stick to each other by hydrogen bonds between hydrogenous bases
Base Bonding Rules
A-T
C-G
A-U
DNA
Sugar is deoxyribose (has one less oxygen than ribose)
Has t no u
Double stranded
Stays in the nucleus
RNA
Sugar is ribose
Has U no T
Single stranded
Can leave the nucleus
Central Dogma of Biology
- DNA is in the nucleus (master copy)
- RNA is a copy of part of the DNA, which can be sent out to different parts of the cell so they can make proteins (working copy)
Central Dogma of Biology (ladder version)
DNA-> transcription (writing down from the same chemical language) -> RNA -> translation (writing down from a different chemical language) -> protein
Chemical
Anything made of atoms
