Other Flashcards
4 parts of a scientific hypothesis
- Testable
- Falsifiable
- Parsimony (simple steps)
- Scope (apply to other situations)
What is Life
Organised genetic unit capable of metabolism, reproduction and evolution
How long ago did earth form
4.5 billion years
Eukaryote
Cells that contain a nucleus and other membrane bound organelles
Prokaryote
Cells without a nucleus
What is an animal (5 things)
- Multicellular, heterotrophic, eukaryotes
- No cell wall
- Nervous and muscle tissue (responsible for impulse conduction and movement)
- Most reproduce sexually
- Begin as zygote and transform into animal through controlled expression of HOX genes
Phylogeny
Evolutionary history of a species or group of related species
Hierarchal Classification
-Domain
-Kingdom
-Phylum
-Class
-Order
-Family
-Genus
-Species
(dear king Philip came over for good soup.)
Why are animal cells bigger than bacteria
Lower chemical constraint of prokaryotes - less energy needed as they do not have to support all the organelles
What governs the size of cell
Cells want to be as small as they can - easier to pick us oxygen and exchange compounds for cells with higher SA:V
Prokaryote vs zygote
Prokaryotes divide to be exactly the same, Contrastingly, The zygote divides and differentiates into a diverse number of cell types
How do animals form (zygote to organism)
Every cell starts with a small zygote that has the potential to develop and change into a full organism - one cell differentiates into a wide range of cell types which all perform different functions in our body.
Plasma Membrane
Phospholipid bilayer
Head - hydrophillic
Tail - Hydrophobic
Flexible, allowing cell to move and migrate, enables selective passage.
Role of Nucleus (4 things)
- Store and preserve DNA
- Organise DNA
- Access DNA to make proteins
- Replicate DNA for cell divison
Structure of nucleus based on its function (protection of DNA
- Solid
- Surrounded by nucelus membrane which regulates passage into and out of DNA
2 ways mutations occur
- Errors during DNA replication
- Direct damage and errors in repair (UV rays, radiation etc)
Endoplasmic Reticulum (ER)
RNA binds to the ER to make proteins that are destined to LEAVE the cell or to be inserted into membranes
Golgi Apparatus
Proteins are sent here that need to leave the cell, they are further modified and then diffuse out of the cell through vesicles.
Mitochondria
Site of cellular respiration - produce ATP from glucose which can be hydrolised to ADP to produce energy
How did mitochondria find its place in our cells
Symbiotic relationship. it’s thought that mitochondria may be able to exist in isolation BUT since oxygen using, non photosynthetic eukaryotic cells need energy, and mitochondria need safety and protection, they may have migrated into cells for symbiosis.
Function of cytoskeleton
involved in transport inside a cell, cellular movement, endocytosis and exocytosis,
What is cytoskeleton
Network of fibres extending throughout the cytoplasm
Microtubules
Thickest tubes
Involved in the maintenance of cell shape, cell motility, chromosome movements in cell division, and organelle movements around the cell.
Microfilaments (actin filaments)
Maintenance and changes in cell shape, muscle contraction, cell motility and division
Intermediate filaments
Cables of fibrous proteins.
-anchor nucleus and other organelles, form nuclear lamina.
Extracellular matrix
Connects cells, provides tissue scaffold and polarity - made up of collagen and glycoprotein fibronectin involved in cell messaging)
Tight Junctions
Barrier due to the binding of plasma membranes of neighbouring cells. (eg, tight barriers between skin cells make us watertight and protect us from the germy world)
Gap Junctions
Channels from one cell to the other (ions sugars and amino acids can pass)
Desmosomes
Strong adhesion - fasten cells together into “sheets” - muscle
Microbiome
Collection of all microbes, bacteria, fungi, viruses, and their genes, that naturally live on and in our bodies
Why is gut microbiome important
- Breaking down food
- Manufacturing Vitamines
- Training our immune system
What is microbiome imbalance linked to
Obestiy, mood disorders, and altered immune response
What is our microbiome influenced by
Diet in infancy (breastmilk vs formula) environment, antibiotics
Why are probiotics following antibiotics essential
Replenish depleted microbiome
Are bacteria in microbiome good or bad
Some are harmful (salmonella) while others are helpful.
Helicobacter pylori
Can trigger formation og gastrointestinal ulcers BUT can have benefits for apetite regulation (all depends on immune system)
Role of microbiome (5)
- Break down food
- Supply gut with energy
- Make vitamins (vitamin K/folic acid))
- Break down toxins
- Protect against pathogens
Microbiome is linked to… (2 things)
Obesity and mental health disorders such as anxiety and depression
How can u alter microbiome
Consume resistant starch, probiotic, or fecal microbial transplantation
Antibiotic effects on microbiome (3)
- Reduced microbial diverstiy and density
- Form antibiotic resitant strains
- Change attributes of microbiome
