A2.2 Cell strcuture + B2.2 Organelles + Compartmentalisation

Question 1

What are common structures of cells ?

Answer 1

Cell membrane
Cytoplasm
DNA
Ribsomes

Question 2

What are the two types of cells

Answer 2

Prokaryotes
Eukaryotes

Question 3

Features of Prokaryotes
(tp coisas differentes)

Answer 3

Lacks nucleus
Lacks cellular internal compartmentalisation
All chemical reactions happen in cytoplasm

Question 4

what are the types of Prokaryotes and what do they resist

Answer 4

Archea- Group of bacteria that lives in extreme enviroments ( volcanic erruptions)

Eubacteria- Lives in optimum enviromental conditions

Question 5

Features of Eukaryotes

Answer 5

Nucleus present

Cellular internal compartmentalisation making small subcellular structures called Organelles

Question 6

How does the Cellular internal compartmentalisation help the Eukaryotes

Answer 6

It creates a specific and optimun enviroment for each cellular process avoiding substrate enzymes and products to mix.

For example DNA is protected inside a nuclear memebrane which avoids contact with cytoplasm metabolic reactions

Question 7

Prokaryotes cell strcutures and its functions

Answer 7

Flagellum- movement

Plasmid- Provides anti biotic resistance

Nucleoid - Circular Free naked DNA

Cell wall - Made of peptidoglycan

Cell membrane- controls the entry and and exit of substances

Pilli - Cell attatchment and DNA transfer

Cytoplam- Chemical reactions

70’s Ribsomes - Protein synthesis

Question 8

Cellular structures of Animals Eukaryotes

Answer 8

Nucleus
Cytoplasm
Mitochondria
Cell Plasma membrane
RER- with attached 80’s Ribosomes
SER
Lysomes
Centrioles
Free Ribsomes
Golgi complex
Secretory vesicles
Transport Vessicles
Cytoskeletons: microfilaments, microtubules, Intermediate filaments

Question 9

what does the Nucleus consists of and its fuctions

Answer 9

Nuclear pore- Nuclear pores are gateways that control the movement of molecules between the nucleus and the cytoplasm.

Nuclear memebrane- encloses the nucleus, providing a barrier that separates the contents of the nucleus from the cytoplasm

DNA

Nucleolus- synthesises of ribsomes

Question 10

Functions of the RER (with attached 80’s Ribsomes) and SER

Answer 10

RER- Synthesise of Proteins that will leave the cell by exocytosis

SER- Synthesise of Lipids

Question 11

Function of

Golgi complex
Secretory vessicles
Transport Vessicles

Answer 11

Modifys the proteins and packages them for secretion

Transport and release molecules inside and outside the cell.

Transports proteins made in the RER to the Golgi

Question 12

What are Cytoskeletons and what are the 3 types

Answer 12

It is a network of protein filaments that provides support, cell movement, and adhesion

Microfilaments
Microtubles
Intermediate Filaments

Question 13

Diffrence between animal cells and plant cells

Answer 13

Animal cells: Have centrioles and lysosomes, but no cell wall or chloroplasts.

Plant cells: Have cell walls, chloroplasts (for photosynthesis), and large vacuoles, but no centrioles.

Question 14

Origin of Cells Processes

Answer 14

Pre biotic earth
Inorganic compounds
Organic monomers
Organic polymers
Self replicating polymers
Polymers in vessicles
First cell

Question 15

What was the pre biotic earth

Answer 15

It had a reducing atmosphere with no O2 and Co2

High levels of ammonia and hydrogen ions

Very high temp
Very high volcanic erruptions
Very high lighting storms
Very high bombarment of asteroids

Question 16

Inorganic compounds are what

Answer 16

are substances that generally don’t come from living organisms and typically don’t contain carbon-hydrogen bonds

H2, NH4, H20

Question 17

What is the process from inorganic compounds to organic monomers

Answer 17

Spontanious generation of simple organic compounds due to energy from high tempreture and lightning

Question 18

What is the name of the evidence for the process from inorganic compounds to organic monomers

Answer 18

Miller- Urey Experiment
It is a appratus that simulated the acient water cycle:

It was preformed to test if inorganic molecules can form organic molecules in specific enviromental conditions in the pre biotic earth

Question 19

Explain the steps of the Miller- Urey Experiment

Answer 19

1- Liquid water plaved in a flask with heat source similuated the acient ocean conditions with high tempretures and present of volcanic erruptions

2- Water vapor is formed simulating evaporation from the ocean and goes up the tube

3- The Pre biotic reducing atmosphere is simulated and the water vapor is mixed with methane, ammonia and hydrogen ( inorganic molecules in the acient atmosphere) and electrical discharge that comes from the electrodes

4- In the condenser the mixture cools down and simulates water condensation

5- After 1 week the mixture turns into a brown liquid which was tested and was found to have simple amino acids and complex of oil hydrocarbons

Question 20

Evidence that simple organic molecules, aminos acids and oil hydrocarbons can form polymer complex organic molecules

Answer 20

Deep sea thermal vents-

Deep sea thermal vents, found near volcanic eruptions, contain complex proteins, carbohydrates, lipids, and RNA.

It is believed that the heat from these environments, combined with a high supply of reducing inorganic molecules, created the ideal conditions for the polymerization of these molecules.

Question 21

Evidence of formation of self replicating polymers

Answer 21

RNA has been the first molecule to self replicate

It contains the gentic code and single stranded molecule which increases efficiency when compared to DNA

RNA has a catalystic property as it can act as Ribozyme (enzyme) catalysing specfic reactions as proteins synthesis

They can regulate proteins which make them self replicating poylmers

Question 22

Evidence of formation of membrane of early cells (Polymers in vessicles)

Answer 22

Creating membrane is the forth step of the origin of cells

Early cell membranes may habe formed from fatty acids which are structually much simpler than phospholipids and may have formed more readily prebiotic enviroment

Free fatty acids would form micelles,

These micelles could join together to form more complex structures, like lipid bilayers, creating basic membranes. These membranes would create enclosed spaces, providing a stable environment for self-replicating molecules and other important molecules needed for early life.

Question 23

How can membranes exist as

Answer 23

Vessicles
Micelles
Bilayers

Question 24

How was the first cell created after formation of membrane of early cells (Polymers in vessicles)

Answer 24

After the formation of membranes and self-replicating molecules, these components would combine into a fully functioning, self-sustaining system. This marks the transition from simple molecules to the first living cell, capable of growth, reproduction, and responding to its environment.

prokaryotic cells

Question 25

What was the Pre biotic atmosphere

Answer 25

The prebiotic atmosphere was likely composed of gases such as methane, ammonia, water vapor, and hydrogen, with little to no oxygen.

Question 26

What are Protocells

Answer 26

Protocells were simple, membrane-bound structures formed from lipids, containing self-replicating molecules like RNA. They provided an enclosed environment for basic metabolic processes, representing a crucial step toward the development of life.

Question 27

what are the structures of the protecell areas

Answer 27

Lipid layers (made of fatty acids) RNA Pool Lipid bound bubble Protocells

Question 28

Where was the Pool of the Protecells found and how do they form what they form

Answer 28

It was found in the oceans in hydrothermal vents in the deep oceans because it contains high temperature and pressure, which are optimum conditions to form vessicles

Question 29

What do the Lipid bound bubble do

Answer 29

trap molecules inside

Question 30

What is the function of the Lysosomes and the Centrioles

Answer 30

Centrioles: These are involved in cell division (helping organize the spindle fibers that separate chromosomes during mitosis and meiosis). Lysosomes: Small organelles filled with enzymes that help break down waste materials and cellular debris.

Question 31

What does the Animal cell have that the plant doesnt

Answer 31

Lysosomes and the Centrioles and larger vacuoles

Question 32

What was the evidence that Protocells could spontaneously form under optimal conditions

Answer 32

The fatty acids assembled into a membranous vessicle with a polymer in the middle being encapsulated

Question 33

What does the The polymer encapsulated in the Protocells contains

Answer 33

Peptide string of amino acids or RNA

Question 34

How did the Protecells spontaneously form under optimal conditions

Answer 34

The polymer being mixed and under the right conditions would create a vesicle that conitaned the RNA and amino acids

Question 35

What is Chemical evidence

Answer 35

It is evidence that was found in the rocks, and therefore contained a fossil-like structure with Isotopes that suggested that there may have been remains of living organisms

Question 36

What are Biomarkers

Answer 36

Biomarkers are organic molecules found in rocks that prove life existed in the past, even if no fossils are visible.

Question 37

What is fossil evidence

Answer 37

consists of preserved remains or traces of organisms that provide direct information about past life, supporting the theory of evolution

Question 38

Structures of the Plant cell

Answer 38

Nucleus Cytoplasm Mitochondria Cell Plasma membrane RER- with attached 80's Ribosomes SER Free Ribsomes Golgi complex Secretory vesicles Transport Vessicles Cytoskeletons: microfilaments, microtubules, Intermediate filaments Amyploplast Vaccole

Question 39

Function of the Amyploplast

Answer 39

Vessicle that stores startch as amylose and amylopectin

Question 40

Function of plama membrane

Answer 40

A lipid bilayer in that contains embedded proteins that regulate what passes in and out

Question 41

What is the RER and its function

Answer 41

a network of internal membranes that synthesis proteins

Question 42

What is the Golgi complex and its function

Answer 42

Stacks of flattened vesicles that package proteins for export from the cell and forms the secretory vesicle

Question 43

What is the Peroxisomes

Answer 43

Vessicles containing oxidative and other enzymes that isolate some chemical activities from the rest of the cell

Question 44

Role of the Nucleolus

Answer 44

Assembles ribosomes Site for genes for RNA synthesis

Question 45

What organelles have double membranes

Answer 45

Nucleus Plasma membrane Mitochondria Chloroplast

Question 46

What organelles have single membranes

Answer 46

Golgi Vessicles Lysosomes Ribsomes Vacuole

Question 47

What organelles have no membranes

Answer 47

Cytoskeleton Cell wall Cytoplasm

Question 48

What organelles have internal membranes

Answer 48

RER SER

Question 49

Microfilaments What is the: Protein subunit Strcuture Functions

Answer 49

Actin Two intertwined strands Maintains cell shape, motility, concentration

Question 50

Intermediate filaments What is the: Protein subunit Strcuture Functions

Answer 50

Fibrous protein Fibers wound with thicker cables Maintains cell shape and anchor nucleus organelles

Question 51

Microtubules What is the: Protein subunit Structure Functions

Answer 51

alpha and beta dimers Hollow tubes Maintains cell shape, mobility, move chromosomes and organelles

Question 52

Cell theory: where do cells comes from

Answer 52

They come from the existing cell in cell division

Question 53

What are the atypical cells: the 4 examples

Answer 53

Phloem sieve tube Red blood cells Skeletal muscles cells Aseptate fungal hyphae

Question 54

Phloem sieve tube: Function Structure about it Result of its structure

Answer 54

They serve to transport dissolved substances such as sucrose around a plant - They have no cell walls - Lack of many organelles (nuclei, ribosomes, mitochondria) Because of the lack of organelles, they can only survive due to the pressure of companion cells which sit along the tube and help maintain the cytoplasm of the tube

Question 55

Red Blood Cells: Function Structure about it Result of its structure

Answer 55

Carry oxygen through the blood - no nucleus so they have more space for oxygen and haemoglobin - Bioconcave shape that gives more surface area to carry more oxygen - Cytoplasm contains haemoglobin More successful transportation of oxygen

Question 56

Skeletal muscles cells Function Structure about it

Answer 56

voluntary movement, maintaining posture, and stabilizing joints - Longer than typical cells for contraction - have multiple nuclei surrounded by a single membrane - have strained nucleus cells formed from multiple cells fused together

Question 57

Aseptate fungal hyphae Function Structure about it

Answer 57

Allows continuous cytoplasmic flow for rapid growth and nutrient transport. Long and narrow branches have cell membranes, cell walls No end walls

Question 58

What is endosymbiosis?

Answer 58

One cell engulfed one and remained inside the cell

Question 59

What are the two processes that are thought to have led the origin of Eukaryotes?

Answer 59

Infoldings of the prokaryotic cell membrane (formation of internal membranes) Theory of endosymbiosis ( one cell engulfing another- organelles)

Question 60

Infoldings of the prokaryotic cell membrane (formation of internal membranes) Explain

Answer 60

Organelles such as endoplasmic reticulum golgi and nuclear envelope are thought to have evolved from inward folds of the plasma membrane of ancestral prokaryotic cells such internal membranes would allow the cell to carry out more complex chemical reactions in separate compartments

Question 61

Theory of endosymbiosis ( one cell engulfing another- organelles) Explain - Mitochondria

Answer 61

One cell lived within the other and become increasingly independent until it could exist as a whole First there would be the ancestral eucharistic cell which has a nucleus and then a ancestral aerobic bacteria would engulf the cell and when the bacteria does it it has its own internal membrane but the outer membrane is still from the eukaryotic cell

Question 62

Theory of endosymbiosis ( one cell engulfing another- organelles) Explain - Chloroplast

Answer 62

For the chloroplast, the ancestral photosynthetic bacteria would engulf an ancestral eukaryotic cell and it would create its own internal membrane but its outer membrane would be from that eukaryotic cell

Question 63

Evidence for endosymbiosis Structural evidence;

Answer 63

Structural evidence; the size and shape of the mitochondria and the chloroplast were very similar to the prokaryotic cell mitochondria and chloroplasts are the only ones that have a double membrane Both of them have the 70 S ribosome which are the same ones found in bacteria where in eukaryotes they have 80 S ribosomes therefore it would have to come from a bacteria

Question 64

Evidence for endosymbiosis Genetic evidence

Answer 64

Both the mitochondria and the chloroplasts have a circular naked DNA which is the one that bacteria also has and their sequences of DNA are also the same

Question 65

Evidence for endosymbiosis Functional evidence

Answer 65

Both the mitochondria and chloroplast can move independently in the cell without the help of cytoskeletons They reproduce independently of the wholesale through processes similar to binary fusion as they have their own DNA Their own circular DNA resists to antibiotics which suggest that they are prokaryotic