Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Cell biology > The eukaryotic cell (lectures 1-4) > Flashcards

The eukaryotic cell (lectures 1-4) Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

What is cell biology?

A

The study of the structures, functions and behaviours of cells

A cell is always derived from another cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the LUCA?

A

Last Universal Common Ancestor

All life forms on earth can be traced back to a LUCA, a single cell organism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Features of eukaryotic cells

A

Highly compartmentalised

Complex end-membranes and cytoskeleton

Are chimeras - cellular and genomic

Share an ancestor that possessed a bacterial endosymbiont that evolved into modern mitochondria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What do phylogenic trees show?

A

Evolutionary history of a group of organisms
Inferred directly from nucleotide or amino acid sequence data
Certain genes are globally distributed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the most widely used phylogenic marker?

A

Small subunit ribosomal RNA (SSUrRNA) gene

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the 2 types of membranes?

A

Endogenous

Exogenous

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Examples of endogenous membranes

A

RER

Nucleus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Examples of exogenous membranes

A

Mitochondria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the archezoa hypothesis?

A

Archezoa is a kingdom proposed for eukaryotes that diverged before the origin of mitochondria

First eukaryotes were anaerobes

Nucleus was invented before the mitochondria was acquired

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

When would the archezoa hypothesis fall?

A

Would fall if we find:

1) Archezoans branch among aerobic species with mitochondria
2) Mitochondrial genes on archezoan genomes
3) Mitochondria-derived organelles in archezoans

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What does the plasma membrane do?

A

Encloses cell content
Separates it from the external environment
Allows different concentrations of substances to be maintained

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are endomembranes and what do they do?

A

Are complex internal membranes

Allow separate compartments to have different constituents and functions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are biological membranes made of?

A

Lipid bilayers

Proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Function of the cytosol

A

Many metabolic pathways

Protein synthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Function of the nucleus

A

Contains main genome

DNA and RNA synthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Function of the endoplasmic reticulum

A

Synthesis of most lipids

Synthesis of proteins for distribution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Function of the golgi apparatus

A

Modification, sorting and packaging of proteins and lipids for either organelles, the PM or secretion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Function of the lysosomes

A

Intracellular degradation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Function of the endosomes

A

Sorting of endocytose material

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Function of the peroxisomes

A

Oxidation of toxic molecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Function of the mitochondria

A

Oxidative phosphorylation

FeS cluster biosynthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Function of the chloroplasts

A

Photosynthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Function of the plasma membrane

A

Barrier functions
Communication with environment and other cells
Passage of molecules in and out of cell
Cell growth, shape change, movement, division

24
Q

Cells integrate genotypes and the environmental cues to generate phenotypes.
What is deterministic and probabilistic?

A

Deterministic - penetrative gene mutation

Probabilistic - complex combination of genes and the environment

25
Q

Most common lipids in eukaryotes

A

Phospholipids
Cholesterol
Glycolipids

26
Q

What are glycolipids?

A

Sugar containing lipids

Face away from the cytosol
Localised to apical side of epithelial cells

27
Q

Why is membrane fluidity important?

A

Needs to be precisely regulated to ensure survival of cell
Lipid composition and temperature influence fluidity hugely

Many organisms can adjust membrane composition in relation to the temperature of the environment

28
Q

Functions of membrane proteins

A

1) Transporters
2) Linkers
3) Receptors
4) Enzymes

29
Q

What is the glycocalyx?

A

The cell coat

Protects against physical, chemical and biological damages

30
Q

Functions of the glycolcalyx

A

1) Protection
2) Adhesion
3) Recognition
4) Storage

31
Q

What is polarised distribution of proteins?

A

When proteins are restricted to specific domains of the membrane and cannot diffuse in the plane of the membrane

32
Q

What are the 3 types of energy driven transport?

A

1) Coupled transport
2) ATP driven transport
3) Light or redox driven transport

33
Q

What are the 3 major types of transport?

A

1) Gated transport
2) Transmembrane transport
3) Vesicular transport

34
Q

Movement between the nucleus and the cytoplasm

A

Nucleur envelope surrounds the nucleus
Nucleus pores
• Allow small molecules to diffuse
• Bigger molecules need specific transport molecules

Through the nucleur pore complex (NPC)

35
Q

What are the different types of protein translocators?

A

TOM - outer membrane

TIM - inner membrane

36
Q

What happens to proteins once in the lumen of the RER?

A

Either:

1) Remain in the RER
2) Travel to other organelles
3) Export to cell surface or exterior to be secreted

Vesicular transport dependent

37
Q

What is vesicular transport essential for?

A

Cell survival

Reproduction

38
Q

What is the golgi apparatus?

A

Located near the nucleus
Pile of membrane stacks (cisternae)
Polarised
Inner cis face - vesicles from RER enter
Outer trans face - export vesicles to organelles/PM

39
Q

What happens within the golgi apparatus?

A 
Further sugars added/removed 
Enzymes located in specific regions 
• Early acting - near cis face 
* Late acting - near trans face 
Proteins leave the golgi in membrane vesicles
40
Q

What is autophagy?

A

Process of destroying internal components

41
Q

Why is autophagy important?

A

Helps maintain health
Homeostasis
Important during normal cell growth and differentiation
Adaptive responses to stress

42
Q

What happens when autophagy goes wrong?

A

Dysfunctional autophagy

Associated with infectious disorders, neurodegenerative disease and cancer

43
Q

What filaments is the cytoskeleton made of?

A

Intermediate filaments
Microtubles
Actin

44
Q

What does the cytoskeleton do?

A

Responsible for cell shape and movement
Positions organelles within the cell
Directs transport between intracellular compartments

45
Q

Intermediate filaments

A

In both the cytoplasm and the nucleus
Provide mechanical strength
Prevent excess stretching
Diameter = 10 nm

46
Q

What are nucleur lamins?

A

IF’s in the nucleus
Lines inner face of the nucleur envelop
Attachment sites for binding proteins and chromosomes
Breaks down during cell division
• Assembly and disassembly regulated by phosphorylation

47
Q

Microtubles

A 
Move chromosomes during cell division 
Intracellular transport 
Drive cilia and flagella 
Rigid and unstable 
Diameter = 25 nm 
Made of tublin monomers 
Grow out from the organising centres 
• Centrosome - normal cells 
• Spindle poles - mitotic spindle 
• Basal body - cilia/flagella
48
Q

How do microtubules assemble?

A 
Assemble from dimers of alpha and beta tubulin
Forms a cylinder of 13 protofilaments
This forms a straw/tube
Tubes are polarised 
• Grow from the positive end 
• Break down from the negative end
49
Q

What are cilia?

A

Hair like extensions
Short extensions
Contain microtubules
Can be mobile or stationary

50
Q

What are microvilli?

A

Localised on the villi (lumen of the small intestine)
Increase SA for absorption
Extension of the plasma membrane
Contain actin filaments to keep upright

51
Q

Actin filaments

A 
Thin and flexible 
Cell motility and contraction 
Maintain cell shape 
Made of actin monomers - use ATP to build 
Diameter = 6-8 nm 
Polar filament
52
Q

How are actin filaments formed?

A 
Filament is polarised 
Monomers of G-actin add to either end 
• More rapidly at the + end 
Polymerisation associated with ATP hydrolysis 
Regulated by actin binding proteins
53
Q

Actin filaments motor proteins

A

Myosins
Globular heads bind ATP
Heads bind to actin filaments and hydrolysis of ATP drives movement
Tails bind structures such as the PM, vesicles and other myosin molecules

54
Q

What is spectrin?

A 
A cytoskeletal protein 
Inner plasma membrane 
Mechanical strength, stability and shape 
Link membranes to the motor proteins 
Forms a scaffold
55
Q

Diameter of cytoskeletal filaments

A

Intermediate filament = 10 nm
Microtuble = 25 nm
Actin filament = 6-8 nm

Cell biology (14 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions