Unit 1: Biochemistry Flashcards

Question

What is phosphorylation?

Answer 1

Transfer of phosphate group Even though the human body consumes its own mass in ATP per day, a highly efficient recycling system exists in the body whereby catabolic processes provide the energy to reconnect the terminal phosphate to an ADP molecule as anabolic processes use the energy ATP releases.

Answer 2

Reaction that produces large molecules from smaller subunits Energy is absorbed Anabolic steroids

Answer 3

Reaction that breaks macromolecules into subunits Energy is released Digestion

Answer 4

A spontaneous change occurs on its own once started and does not require a continual input of energy. ## Footnote Example: Once a match is lit, it will continue to burn without the continual addition of energy.

Answer 5

Equilibrium

Answer 6

Plants in a hypotonic environment have increased turgor pressure, a sign of a healthy plant

Answer 7

Plants in a hypertonic environment wilt The cell membrane shrinks away from the cell wall. The cell may die Known as plasmolysis

Answer 8

Water concentration inside the cell is equal to the concentration outside the cell Net movement = 0 Most living cells on earth, → ideal situation

Answer 9

Water concentration outside the cell is greater than the water concentration inside the cell As water keeps diffusing into the cell the cell expands and may burst Net movement = outside → inside Placing a single celled organism (98% water) into distilled water (100%) Net movement: outside -> inside

Answer 10

Water concentration inside the cell is greater than the water concentration outside the cell As water keeps pumping out, the cell shrivels and may die (dehydrate) Net movement = inside → outside Placing freshwater amoeba into salt water

Answer 11

Active process by which cells ingest (import) materials Cell membrane pinches (folds) in on itself to create a vesicle (membrane enclosed sac) which moves into the cell Phagocytosis (cell eating) Movement of large molecules into the cell White blood cell engulf bacteria cell Pinocytosis (cell drinking) Transport of fluid droplets into the cell Fat droplets entering a cell

Answer 12

Active process by which cells export materials (movement) out of the cells maintain filled vesicles fuse with cell membrane & contents are released Specialized cells in pancreas secrete hormone; insulin *Exocitosis restores the membrane removed by endocytosis*

Answer 13

Protein pumps found in the membrane can move substances against the concentration gradient These pumps utilize energy from metabolism, specifically in the form of adenosine triphosphate (ATP) This pump is found in animal cells 3 Na ions within the cell bond to the transporter protein at the same time as 2 K ions bind on the outside of the cell (all are positively charged) This binding causes protein to change shape Its new shape forces the Na ions out and the K ions into the cell Once ions are released, the protein changes back to its original shape A high concentration on Na builds up outside the cell Na diffuses back inside through a carrier protein This carrier protein is shaped so that Na can only diffuse back inside if it has bonded with a glucose molecule Na returns to the cell down the concentration gradient and this provides the means for glucose to enter the cell

Answer 14

Movement across the cell membrane that requires the cell to expend energy and moves particles against the concentration gradient Unlike passive transport it does not move with the concentration gradient A cell often must maintain an internal environment vastly different from its external environment Nutrients must be concentrated inside the cell, waste must be completely removed The amount of energy the cell expends depends on the concentration gradient Kidney cells need to pump glucose and amino acids into the blood Intestinal cells need to pump nutrients out of the intestines and into the blood

Answer 15

will only accept non charged particles

Answer 16

will accept charged particles The proteins have a tunnel like shape and only allow ions that are small enough and with the correct charge to pass A positively charged channel will only allow negatively charged ions to pass and vice versa

Answer 17

the method of diffusion used y molecules that are simply too large to pass through the membrane by diffusing Specialized transport proteins imbedded in the membrane move the molecule across Transport proteins only recognize and move one type of dissolved molecule (very selective due to structure) This process is still driven by a concentration gradient and molecules move from an area of high concentration to low concentration with no use of energy required

Answer 18

the diffusion of water molecules across a selectively permeable membrane from an area of high concentration to an area of low concentration Solute → substance dissolves in water Solvent → substance which the solute is dissolved in

Answer 19

The movement of molecules across a semipermeable membrane that does not require the cell to expand any energy Types of passive transport are: Diffusion, osmosis, and Facilitated diffusion Diffusion → the movement of particle down a concentration gradient from an area of high concentration to an area of low concentration Diffusion is caused by molecular collisions As the particles collide they bounce around in all directions and move further apart with equal frequency Areas of high concentration will have more collisions then areas of low concentration Diffusion rates are affected by temperature and pressure (increased rates as temp or pressure increases) Both oxygen and carbon dioxide are free to diffuse across a cell membrane

Answer 20

Brownian Motion → the random movement of particles Particle theory All matter is made up of particles There are spaces between particles Particles are always moving

Answer 21

Total amount of energy in the universe is constant Energy cannot be created or destroyed but only converted from one form to another—change in states If an object or process gain an amount of energy it does so at the expense of a loss of energy somewhere else in the universe

Answer 22

Entropy (randomness/disorder in energy or a collection of objects) of the universe increases with any change that occurs

Answer 23

Entropy (randomness/disorder in energy or a collection of objects) of the universe increases with any change that occurs

Answer 24

Chemical reaction in which the chemical potential energy of the product is less then the energy of the reactants (energy has been released)

Answer 25

Chemical reaction in which the chemical potential energy of the products is more than the energy of the reactant (energy has been absorbed)

Answer 26

oxidization reduction Reactions involving a transfer of one or more electrons from one reactant to another Oxidization is the loss of electrons Reduction is the gain of electrons Energy is always lost during oxidization and gained during reaction Application Oxidization of food molecules releases energy used to maintain body temperature and muscle contraction

Answer 27

Water is a molecule that is essential to life that makes up 50-90% of nearly all organisms. Water is a polar covalently bonded molecule (uneven sharing of electrons). The polar nature of water allows water molecules to form weak bonds with each other called Hydrogen Bonds

Answer 28

attachment to self As a result of hydrogen bonding, water molecules tend to stick together Allows for transport of water against gravity in plants Allows for surface tension to occur on the surface of water

Answer 29

Water molecules stick to other polar molecules

Answer 30

Water requires a large amount of energy transfer to produce a change in temperature Protects cells from rapid temperature change and provides stable environment for cell reactions

Answer 31

Hydrogen bonding causes liquid water to absorb a lot of thermal energy and turn into water vapour (gas) Many organisms, including humans, dissipate body heat by evaporation of water to cool down (sweating)

Answer 32

Ice is less dense than liquid water (ice floats) due to its expansion upon freezing Allows aquatic ecosystems to survive in the winter since bodies of water freeze from top to bottom

Answer 33

DNA & RNA are nucleotide polymers Adenine and thymine bond together Apples in the trees Cytosine and guanine bond together Cars in the garage Pyrimidines → nitrogenous bases with a single ring Adenine and Guanine Purines → nitrogenous bases with double rings Cytosine and Thymine

Answer 34

Phosphodiester bonds hold the phosphate group of one nucleotide and the hydroxyl group attached to the number 3 carbon of the sugan on the adjacent nucleotide The two strands of DNA are held together by hydrogen bonds between the nitrogenous bases on adjacent strands Hydrogen bonds only form properly if one strand is upside down. Said to run antiparallel

Answer 35

Protein Structure Primary The sequence of amino acids Changes in the primary structure can alter the proper function of a protein molecule Protein function is tied to their 3-D structure Secondary Due to the colliding/folding caused by hydrogen bonding between R-groups This forms what is called α (alpha) helix or β pleated sheet Tertiary A folded individual peptide is formed This is due to more bonding or replenish between the R-groups and the polypeptide and its environment This is stabilized by: Hydrogen bonds Ionic bonds Disulfide bridges Quaternary Formed by the interactions of 2 or more polypeptides (ex: hemoglobins) Structure determines the Function

Answer 36

Used to build cell structures and during chemical reactions (enzymes) Not generally used for energy Composed of hydrogen, carbon, oxygen, nitrogen and sometimes sulfur atoms Proteins are found in chicken, nuts, beef, fish, and tofu Proteins are the most common organic molecule in living things and are also the most diverse Made up of subunits called amino acids. The sequence of amino acids determines the type of protein

Answer 37

Amino acids have An amino group Carboxyl group Hydrogen Side chain (R-group) Many amino acids joined together are known as polypeptides. The molecules are held together by bonds called peptide ponds Peptide bond Formed by the joining of amino end of the molecule to the carboxyl end of another by dehydration synthesis 8 amino acids are essential since our body cannot synthesize them (we get them from our diet). We can synthesize the other 12. All 20 amino acids differ in their R-group. The R-groups make the amino acids polar, nonpolar, or electrically charged

Answer 38

a unique lipid (steroid) Used by the body to produce hormones, both male and female sex hormones Important part of the cell membrane Too much cholesterol can combine with other fats to produce plaque with has the ability to block arteries Compact hydrophobic molecule containing 4 fused hydrocarbon rings and one hydroxyl functional group

Answer 39

Saturated fats Single bonds between carbon atoms (full of hydrogen atoms) Lard & butter Unsaturated fats Have double bonds between at least two carbon atoms (loss of hydrogen atoms) Oil

Answer 40

Lipids are composed of hydrogen, carbon and oxygen atoms. There are three groups of lipids Fats, oils, and waxes Phospholipids Steroids

Answer 41

They are an energy source, in which it is more difficult to break down the carbohydrates. Thus 1 gram of lipids has twice as much energy as 1 gram of carbohydrates or proteins. Lipids Aid in vitamin absorption Insulate the body Protect internal organs Cell membranes main component Act as the raw materials when synthesizing hormones and other chemicals need by the body Insoluble in water Glycerol 3 carbon chain attached to a hydroxyl group Fatty acid Hydrocarbon chains containing a carboxyl group at one end Lipids are produced via dehydration synthesis between the hydroxyl group on the glycerol with the carboxyl group on the fatty acid → producing an ester linkage Triglycerides are the most common form of lipid and are composed of a glycerol molecule and three fatty acids

Answer 42

Polysaccharides Monosaccharide polymer composed of monosaccharide subunits held together by glycosidic linkages (ether) Chitin, amylase, amylopectin (starch), cellulose α (Alpha) glucose → the OH lies below the plane of the ring β (Beta) glucose → the OH lies above the plane of the ring There is a 50% chance that the OH will end up below or above the plane of the ring

Answer 43

2 simple sugars bonded together to form a glycosidic linkage (ether) Sucrose

Answer 44

Simple sugars, contain either a carbonyl aldehyde or carbonyl ketone and a hydroxyl function group Glucose

Answer 45

Carbohydrates are composed of carbon, hydrogen and oxygen atoms in the ratio of 1:2:1, (C6H12O6). Composed of single sugar molecules or chains of such sugar molecules Most important energy source of food which is obtained from the intake of food Carbohydrate are found in potatoes, bread, corn, rice, fruit and pasta The word ‘saccharide’ means sugar. Most sugars end with ‘ose’ Glucose is found in all cells & is our primary energy source Glucose and fructose are the common saccharide Sucrose is the makeup of glucose and fructose

Answer 46

Common polysaccharides Starch → storage form of carbohydrates in plants Cellulose → forms cell walls of plants Glycogen → storage form in animals All disaccharides and polysaccharides are formed by a process called dehydration synthesis (the removal of water) to join many monosaccharides Maltose → glucose + glucose Lactose → glucose + galactose Sucrose → glucose + fructose

Answer 47

Group of atoms with characteristic properties. Polar (made up of atoms with differing electronegativities) Hydrophilic → water loving Functional groups determine the overall physical properties of the molecule such as solubility, melting and boiling point. Function groups make up the most reactive region of the molecule and will dictate how the molecule reacts chemically