Molecules, Genes and Cells

B-oxidation

Lipids oxidised into 2C segments

Intermembrane space

In the mitochondria (eukaryotes)

Periplasmic space

Between cell membrane and cell wall (archaea/bacteria)

pH gradient

In the matrix; Basic

In the intermembrane space: Acidic

Chemiosmotic theory

ETC pumps H+ ions across the inner mitochondrial membrane

ATPase

Hydrogen channel and ATP synthesis enzyme

Hypotonic

Concentration of solutes is higher inside the cell than outside

Hypertonic

Concentration of solutes is higher out of the cell than inside

Endergonic

Absorption of energy

Exergonic

Release of energy

Coupled reactions

If the energy released > required, then reactions can be coupled (energy released can be used by another reaction)

ATP composition

Sugar ribose, base adenine and chain of 3 phosphate groups

Ubiquitous

Universal

Phosphorylation

Phosphate groups from ATP is transferred to another molecule

Transition state

The event which bonds break

Cofactors

Non-protein that binds to enzyme to help with its funcion

Organic cofactors

Coenzymes

Inorganic Cofactors

Ions of transition metals

Emergent properties

New properties that arise with each step upwards in the hierarchy of life

Biosphere

Sum of all the planet’s ecosystems inhabited by life

Amphipathic

Having both hydrophilic and hydrophobic regions

DNA

Contains genetic material

Genes

Unit of hereditary information consisting of specific nucleotide sequences

Gene expression

information encoded in DNA directing synthesis of proteins

Genome

Genetic material of an organism or virus

Genome sequence

Entire sequence of nucleotides in an organism’s DNA or RNA

Proteome

Entire sets of proteins expressed

Producers

Produces organic compounds from CO2

Ecosystem

All organisms in a given area as well as abiotic factors

Abiotic

non-living

Biotic

Living

Evolution

Species accumulating differences from ancestors as they adapt to their environment

Natural selection

Individuals with certain traits tend to survive at higher rates

Metabolism

A series of chemical pathway that build or break complex molecules

Catabolic pathway

Break down complex molecules

Anabolic pathway

Build complex molecules

Entropy

Measure of molecular disorder or randomness

Genetic Variation

Individuals within all species vary in their phenotypic traits

Mutation

A change in the nucleotide sequence of an organism’s DNA

Neutral variation

Variation that does not provide a selective advantage or disadvantage

Ribosomes

Carry out protein synthesis

Nucleoid

Region where cell’s DNA is located in prokaryote

Flagella

Locomotion organelles

Nucleolus

Inside nucleus made up of RNA and proteins where ribosomes are made

Nuclear pore

Regulates the transport of molecules between nucleus and cytoplasm

Rough ER

Protein synthesis

Smooth ER

Lipid synthesis

Golgi apparatus

Packages proteins into vesicles to targeted destinations

Exocytosis

Release materials to the outside of the cell via vesicles

Endocytosis

Engulfment materials from the outside of the cell via vesicles

Pinocytosis

Engulfment of liquid into a cell via vesicles

Phagocytosis

Engulfment of food particles into a cell via vesicles

Lysosomes

Break down excess or worn out cell parts

Vacuoles

Storage of water

Mitochondria

Site of cellular respiration

Chloroplast

Site of photosynthesis

Cytoskeleton

Spatially organises the contents of the cell

Descent with modification

Shared ancestor with accumulated differences

Eukaryotic

Plants, Animals, Fungi and Protists

Prokaryotic

Bacteria, Archaea

Gram positive bacteria

Retain violet dye, due to peptidoglycan on the outer surface

Gram negative bacteria

Does not retain violet dye, due to peptidoglycan being sandwiched between lipid layers

Why are prokaryotes so successful?

Rapid evolution due to rapid reproduction resulting in diverse adaptations

Chloroplasts divide like cyanobacteria

Uses bacterial cell division proteins

Autotrophic

An organism that creates it’s own food source

Heterotrophic

An organism that cannot make their own food

Excavata

Parasitic, predatory and photosynthetic species

Stramenopila

Extremely diverse lineage, many photosynthetic

Alveolata

Membrane-lined sacs regulate diffusion across plasma membrane

Rhizaria

Move and feed by pseudopodia

Pseudopodia

Projections fom organism

Fungi closely related to…?

Closely related to animals than to plants

Animals evolved from choanoflagellates

Protist group closely related to animals

Cell Communication

Ability for cells to receive a signal, process it and trigger a response

Cell Junctions

Allow molecules to pass readily between adjacent cells without passing plasma membranes

Cell surface molecules

Surface molecules on adjacent cells interact with each other

Chemosensory GPCRs

Receptors for external sensory e.g. taste

Signal Transduction

Chains of molecular interactions where one molecule activates another, which activates another… leading to a cellular response

Innate Memory

‘Memory’ of previous pathogen and gives a higher response to the secondary exposure to the same pathogen