Bio Exam Revision

biomass

organic matter from living thing (can be used as fuel source)

feedstocks

raw materials used to produce biofuel (carbs based from plants - cellulose, starch), produced from: food crops, agricultural waste, food waste etc.

biodiesels

fuels made from fats/oils

structural genes

code for proteins involved in structure and function

regulatory genes

control activity of other genes, often code for repressor proteins which bind to promoter region and prevent transcription

RNA processing in mRNA strand

• introns removed

• poly-a-tail added

• methyl cap added

• final mRNA produced

protein groups

• globular (3D rounded shape)

• fibrous (long structure)

CRISPR

clustered regularly interspaced short palindromic repeats

PAM

protospacer adjacent motif

pathogen

disease causing agent

NK cells

induce apoptosis

primary lymphoid organs

thymus, bone marrow

secondary lymphoid organs

lymph nodes, tonsils and spleen

Start codon

AUG - met

stop codon

UAA, UAG, UGA

Species

A group of similar organisms that can interbreed in nature and produce vigorous, fertile offspring.

Subspecies

different races of the same species, who do not interbreed directly (gene flow can still exist)

gene pool

genetic makeup of a population, includes sum of all alleles for different genes present in a population

index fossil

fossils that had wide geographic distribution and existed for relatively short period

Half Life

time taken for half of parent isotope to decay into its daughter isotope

Absolute dating - Carbon 14

decays to nitrogen 14, half life is 5700 yrs, used for fossils less than 50,000 yrs old

molecular clock theory

greater difference in nucleotides/amino acid sequence indicates more time for mutations to occur and accumulate and more time since divergence from a recent common ancestor

Competitive Inhibition

binds to active site and competes with substrate for binding to enzyme

Non-competitive Inhibition

Inhibitor does not bind to the active site but causes change in 3D shape of the enzyme and therefore the shape of the active site. This prevents enzyme from functioning.

LDS

• in thylakoid membranes of grana in chloroplasts of mesophyll cells

• light energy is absorbed by chlorophyll

• water is split into H ions and oxygen by light energy, electrons are released

• H ions loaded onto NADP+ to form NADPH

• electrons form ATP from ADP+Pi

• oxygen diffuses out of grana and released from leaf from open stoma

LIS

• CO2 enters through stomata and diffuses into mesophyll cell and moves into stroma of chloroplast

• Loaded carriers (NADPH) and ATP move from grana to stroma for light dependent stage

• CO2 enters calvin cycle in C3 plants

• Unloaded carriers (ADP+Pi and NADP+) move back into light dependent stage to pick up H+ and e-

Light Wavelengths

• white light contains all wavelengths of all light and has highest photosynthesis rate

• red and blue light are absorbed best and have higher photosynthesis rates than other colours

• green is not absorbed by chlorophyll and is reflected

RuBisCO

• an enzyme in first step of Calvin cycle

• catalyzes reaction between RuBP and CO2 (results in carbon fixation)

C3 plants examples and conditions

• rice, wheat, soybeans, all trees

• temperate environment (low temp, water available)

Photorespiration in C3 plants

In high light conditions, there will be high temps resulting in oxygen dissolving in the cell and binding to rubisco resulting in photorespiration

Carbon fixation in C4 and CAM plants

they fix CO2 from environment into malate using pep-carboxylase

C4 plants

• high temps, humid, high daytime light intensity (tropical)

• LDS and LIS physically separated 

• LDS in mesophyll cells

• LIS in bundle sheath cells

CAM plants

• high daytime temps, intense sunlight, low soil moisture (arid)

• cacti, succulents

• carbon fixation at night

Purpose of Cellular Respiration

process that releases useable form of ATP from glucose

Aerobic Respiration Steps

1. Glycolysis

2. Kreb’s Cycle

3. Electron Transport Chain

Glycolysis

• occurs in cytosol

• glucose broken down to form 2 pyruvate, needs 2ATP and 2NAD+

• energy released to form 2ATP, 2NADH

• loaded molecules move to cristae for electron transport chain

Kreb’s Cycle

• occurs in matrix of mitochondria

• 2 pyruvate forms 6CO2

• energy released to form 2ATP, 8NADH, 2FADH2

• loaded molecules taken to cristae for electron transport chain

Electron transport chain

• occurs in cristae of mitochondria

• e- and H+ from NADH and FADH2 are passed along series of cytochromes

• O2 is the final electron acceptor and combines with H to form H2O

• energy released to drive ATP production (26 or 28 ATP)

Aerobic Respiration ATP yield

30 or 32, isnt efficient due to ATP used during transport of substance into mitochondria

Factors affecting rate of cellular respiration

temp - as increases, more collisions, more kinetic energy, therefore increased rate of reaction, enzyme denatures - not cell

glucose availability - more glucose, faster rate of reaction till plateau

oxygen concentration - absence is anaerobic respiration, as increases, rate of aerobic respiration will increase up to plateau