Brainscape's Knowledge GenomeTM

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


See full index

SCIE1106 > Eukaryotic & Prokaryotic Cells > Flashcards

Eukaryotic & Prokaryotic Cells Flashcards

1
Q

Cells

A

These comprise all living things. They are small membrane-bound units. They have the ability to divide, grow, respond to stimuli, undergo energy conversion and highly specialised. There is a large diversity in how these make up organisms with some only requiring one and others having billions. These are all composed of the same sorts of molecules and all carry out the basic biochemistry.

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

Single-Celled Organisms

A

These are organisms that are made up of 1 cell.

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

Multi-Celled Organisms

A

These are organisms made up of many cells that make up tissues, which then make up organs, which completes the make up for the entire organism.

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

Basic Cell Chemistry

A

All cells store their genetic material and have the same genetic mechanisms. Their genetic material is replicated and passed on to the next generation via cell division. This information flow uses the same chemical machinery in all cells. All of these also contain the same set of 20 amino acids in the proteins they produce.

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

Cell Similarity

A

All organisms have the same common ancestor which lived 3.5 billion years ago. Over time however mutation and selection of descendent cells through evolution resulted in divergence, modification, adaptation, specialisation and this is on-going.

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

Prokaryote

A

These are cells that were formed without the evolution of a nucleus. These can be split into 2 categories of organisms which are Eubacteria and Archea bacteria. Divisions between these 2 groups is based on molecular biological characterisations they are as different from each other as they are from eukaryotes. These are the most diverse group of cells and successfully inhabit many different environments. They exhibit many different forms e.g. spherical, rod-shaped spiral etc. They can also be organotrophic, phototrophic or lithotrophic.

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

Eukaryote

A

These are cells that were formed with the evolution of a nucleus. These cells can form unicellular (protists and yeast) and multi-cellular (animals, plants, fungi) organisms.

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

Eubacteria

A

Referred to as ‘true bacteria’. These are found in environments that are familiar to us e.g. Escherichia coli (E-coli) in your gut.

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

Archea Bacteria

A

These are found in hostile environments as well as in more familiar ones.

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

Organotrophic

A

These cells use any organic molecule as an energy source.

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

Phototrophic

A

These cells use light as an energy source.

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

Lithotrophic

A

These cells use inorganic molecules as an energy source.

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

Prokaryote Features

A
  • These are ‘simple’ cells.
  • They are only a few micrometers long.
  • They typically have a tough protective cell wall.
  • They have a plasma membrane.
  • There is essentially no membrane-bound organelles.
  • They don’t have nuclei but have circular DNA free in cytosol.
  • They have many ribosomes.
  • They may have a flagellum (small tails used for movement).
  • They can reproduce quickly (some can divide every 20 minutes).
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Plant Cells

A

These are typically more rigid cells because of strong cell walls. They also have different organelles to animal cells e.g. chloroplasts for photosynthesis.

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

Animal Cells

A

These are typically less rigid as they don’t typically have cells walls. These don’t typically have organelles that aren’t also found in plant cells.

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

Ribosomes

A

These are cell organelles found in both prokaryotes and eukaryotes. They act as the sites for protein synthesis and are made up of large complexes consisting of proteins and ribosomal RNA (rRNA). These are typically larger in eukaryotic cells (80S) compared to prokaryotic cells (70S). In eukaryotes there are 2 populations with some being cytosolic meaning they are free or attached to endoplasmic reticulum and others being on mitochrondria or chloroplasts (70S).

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

Cytosolic Ribosomes

A

These ribosomes are found within eukaryotic cells and are located either free in cytoplasm or attached to endoplasmic reticulum. These are the larger type (80S).

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

Mitochondria/Chloroplast Ribosomes

A

These ribosomes are found within eukaryotic cells are are located either on mitochondria (plant and animal cells) or chloroplasts (plant cells). These are the smaller size (70S) which is the same size as in bacterial (prokaryotic) cells.

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

Membranes

A

These are found in both prokaryotic and eukaryotic cells. This is formed by a bilayer of phospholipids with an asymmetrical arrangement in the 2 halves. There are also integral and peripheral proteins associated with the bilayer.

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

Integral Proteins

A

These are embedded within the bilayer membrane.

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

Peripheral Proteins

A

These are attached loosely to the bilayer.

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

Plasma Membrane

A

This is found in eukaryotes and in bacteria. It is important for the capacity for movement, importing and exporting different molecules and for receiving information.

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

Membrane Selectivity

A

Membranes are selectively permeable. Small hydrophobic and small uncharged molecules can cross the membrane freely. Larger uncharged polar molecules and charged solutes must interact with transmembrane membrane proteins (transporters) in order to cross the phospholipid bilayer.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Carbohydrate Groups

A

These come in glycolipid and glycoprotein form. They have external (non-cytosolic) roles in cell-to-cell communication, protection from chemical and mechanical damage and a role as adhesives.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Glycolipid

A

Carbohydrate groups that are attached to lipids.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Glycoprotein

A

Carbohydrate groups that are attached to proteins.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Membrane Compartmentalisation

A

In eukaryotes the membranes separate cells from their environments and separate organelles from each other and from the cytosol. Double membranes surround the nucleus, mitochondria and chloroplasts.

28
Q

Single-Membrane Bound Organelles

A

These specific organelles are the endoplasmic reticulum (ER), golgi, and different vesicles (secretory vesicles, endosomes, lysosomes, microbodies e.g. peroxisomes) and vacuoles in plants.

29
Q

Endomembrane System

A

This includes the nuclear membrane, ER, Golgi, transport vesicles, plasma membrane, endosomes and lysosomes and vacuoles. All of these are involved in the movement of substances around the cell and in/out of the cell.

30
Q

Nuclear Membrane

A

This is formed by the ER which is a single-membraned organelle however this is a double-membraned organelle. This double-membraned appearance is due to the fact the ER folds back on itself in order to form 2 layers. This means this is not a true double membrane but is 2 layers of single-membraned layers attached together.

31
Q

Endoplasmic Reticulum (ER)

A

This organelle is a network of sacs and tubules (cisternae) which are found throughout the cytosol which are involved in the synthesis of most cell membrane components and molecules exported from the cell. This is divided into 2 types which are rough and smooth.

32
Q

Rough ER

A

This organelle is described as rough due to its appearance due to the large presence of ribosomes. It is involved in protein synthesis and the addition of carbohydrates to proteins. This is the ER that is continuous with the nuclear membrane.

33
Q

Smooth ER

A

This organelle is described as smooth due to the lack of ribosomes giving it an even and unmarked appearance. It is involved in the synthesis of lipids.

34
Q

Golgi Apparatus

A

This organelle is made up of stacks of flattened sacs (cisternae) with one or more being present in each cell. They are involved in the synthesis and packaging of molecules to be exported from the cell especially the routing of newly synthesised proteins to their correct cellular locations. This organelle is associated with many transport vesicles. This also have a distinct orientation with cis and trans faces.

35
Q

Golgi Cis Face

A

This face of the organelle is adjacent to the ER and the vesicles that arrive from the ER. This is the receiving face.

36
Q

Golgi Trans Face

A

This face of the organelle points toward the plasma membrane and is involved in transport vesicles pinching off and fusing with cisternae, carrier proteins being modified with additional sugar groups and the correlation of specific enzymes at specific locations of cisternae in order to catalyse the reactions for the sugar-modification of proteins.

37
Q

Microbodies

A

These are single-membrane bound which contain oxidative enzymes. In animals and plants they are the sites of detoxification. In plants it is also the sites for detoxification for photorespiration (carbon recycling) and the conversion of stored fats into sucrose during germination of some seeds. In animals there are many found in the liver.

38
Q

Exocytic Pathway

A

This is the outward path which is involved in moving substances out of the cell.
1. The pathway involves proteins synthesised on rough ER and glycosylated.
2. Vesicles containing glycoproteins then bud off the ER and fuse with the cis face of the Golgi cisternae.
3. The glycoproteins are further glycosylated as they travel through the cisternae of the Golgi via vesicle budding and fusion.
4. At the trans face of the Golgi the vesicles are directed toward the plasma membrane or a lysosome/vacuole for removal from the cell.

39
Q

Endocytic Pathway

A

This is the inward path which is involved in moving substances into the cell. This involved the ingestion and degradation (recycling) of extracellular molecules.
1. regions of the plasma membrane containing molecules to be degraded ud inward to form vesicles.
2. These vesicles fuse with early endosomes.
3. These molecules are degraded in lysosomes/vacuoles.
4. Some degraded products can be reused by the cell.

40
Q

Vacuoles

A

This is an organelle found only in plant and some yeast cells which are the sites of degradation. These can also store organelles, act as detoxification sites and are involved in pigment deposition. This is due to the plants inability to move and release waste meaning it requires storage for waste materials and those materials which are required later.

41
Q

Double Membrane Bound Organelles

A

These are the nucleus, mitochondria and chroloplasts. They contain 2 layers which surround them.

42
Q

Nucleus

A

This is surrounded by a double membrane which is continuous with the ER. It isn’t technically a true double membrane but a single membrane looped over itself. The membrane is interrupted by pores which allows the passage of selected molecules between the cytosol and nucleus. This contains most of the cellular DNA

43
Q

Heterochromatin

A

DNA and proteins which is highly condensed even during interphase making it inaccessible for DNA transcription making it inactive. This state changes depending on what genes are required.

44
Q

Euchromatin

A

DNA and proteins which aren’t condensed until mitosis. This makes transcription possible meaning this DNA is more active. This state changes depending on what genes are required.

45
Q

Nucleolus

A

This is a dense structure found inside the nucleus which typically contains the genes for ribosomal RNA (rRNA) synthesis and it is the site of this process as well as ribosomal subunit assembly.

46
Q

Mitochondria

A

This organelle is double membraned and is the site of cellular respiration and major energy (ATP) production in a process known as oxidative phosphorylation. This contains both an inner and outer membrane with different structure and functions.

47
Q

Mitochondrial Matrix

A

This is the region of the mitochondria not taken up by membranes. This contains DNA known as the mitochondrial genome which codes for mitochondrial tRNA, mitochondrial rRNA, mitochondrial mRNA and proteins for DNA synthesis and oxidative reactions. Mitochondrial ribosomes 70S same size as in bacteria. It contains enzymes for the tricarboxylic acid (citric acid, Krebs) cycle.

48
Q

Outer Mitochondrial Membrane

A

This is smooth and permeable to ions and small molecules.

49
Q

Inner Mitochondrial Membrane

A

The inner membrane is highly folded (cristae) which is impermeable and transport protein control substrates movement across the inner membrane. This contains an electron transport chain and ATP synthase. It has a large surface area.

50
Q

Chloroplasts

A

This organelle is double membraned and is the site of photosynthesis in plants which undergoes 2 sets of reactions involving light harvesting and carbohydrate production. These have an outer membrane and inner membrane.

51
Q

Inner Chloroplast Membrane

A

This is impermeable and is where transport proteins control the movement of substrates across this system.

52
Q

Thylakoids

A

These are found within the inner membrane of chloroplasts which are formed by a folded internal membrane system. These folded stacks are called grana. It contains light-harvesting pigments, electron transport chain and ATP synthase.

53
Q

Lumen

A

These are found within the inner membrane of chloroplasts which are the spaces between the thylakoids.

54
Q

Stroma

A

The are found within the inner membrane of the chloroplast which is the space not taken up by the thylakoid membranes. It contains DNA which codes for tRNA, rRNA, mRNA (for proteins, DNA synthesis and photosynthesis). The ribosomes found within are 70S which are the same as bacteria. The enzymes necessary for carbohydrate production are also found here.

55
Q

Endosymbiosis

A

An ancestral eukaryotic cell ingested, but didn’t digest an aerobic bacterium which over time evolved into a mitochondria. Eukaryotic cells later ingested a photosynthetic bacterium without digesting it and over time this evolved into a chloroplast which became plant cells.

56
Q

Energy Production 1

A

First you eat food which is then broken down by digestive enzymes with protein into amino acids, polysaccharides to simple sugars and fats to fatty acids.

57
Q

Energy Production 2

A

The broken down products enter cell cytosol for gradual oxidation into pyruvate and production of some energy (ATP) and reducing molecules (NADH). The pyruvate (along with some amino acids and fatty acids) then enter the mitochondria. These molecules are oxidised to form acetyl CoA (coenzyme) which then enters the Krebs cycles.

58
Q

Energy Production 3

A

The acetyl CoA is then further oxidised by the citric acid cycle. This produces CO2 (diffuses out of mitochondria through membranes) and NADH and FADH2 (these have strong reducing power due to the hydrogen they contain). Certain amino acids can enter the cycle without conversion into acetyl CoA to form the CO2 and NADH or FADH2.

59
Q

Mitochondria Electron Transport Chain (mETC)

A

The NADH and FADH2 have strong reducing power (high energy electrons). They donate these electrons to the ETC in the inner mitochondrial membrane where they move through the ETC which consists of multiprotein complexes. After the donation of electrons the remaining hydrogens are combined with O2 to form H2O. The energy from the electrons lost by NADH are used to pump protons out of the matrix. The intermembrane space become acidified with the extra protons so in order to maintain pH the protons are moved into the ATP synthase complex due to the concentration gradient. When the proton enters the complex another part of this complex brings in an ADP and phosphate molecule. The energy from the proton moving through the complex is then used to combine the ADP and phosphate to form ATP which is released.

60
Q

Light Harvesting Reaction

A

This occurs within chloroplasts in which light energy is collected by pigments in the antenna complex in the thylakoid membranes. This electrons gathered from the breakdown of water using the light energy enters another ETC. Some of the energy from these electrons is then used by an enzyme complex in order pump protons into one area. The remaining electrons are combined with NADP to form NADPH. These protons then enter an ATP synthase complex due to the concentration gradient. The energy of the movement of the proton through the complex is then used to combine the ADP and phosphate molecules in order to form ATP.

61
Q

Chloroplast Electron Transport Chain (cETC)

A

During electron transport the proteins move across the thylakoid membranes from the stroma into the thylakoid lumen which generates a concentration gradient. ATP is synthesised as protons move back across the membrane from the thylakoid lumen into the stroma through the chloroplastic ATP synthase.

62
Q

Carbohydrate Production in the Chloroplast

A

This involves a process called the Calvin cycle which uses NADPH and ATP produced during the light reaction in order to synthesise carbohydrates from atmospheric CO2 in the stroma. The enzyme Rubisco catalyses the first reaction in the Calvin cycle.

63
Q

Rubisco

A

This is the most abundant enzyme in the world.

64
Q

Cytoskeleton Overview

A

This is a network of protein filaments that extends throughout the cytoplasm. It functions for support, shape, motility, intracellular transport, chromosome movement, cell division and are dynamic (continuously reorganised). There are 3 types of components which are actin filaments, intermediate filaments and microtubules each is formed from protein subunits.

65
Q

Actin Filaments

A

The are found in all eukaryotic cells. These function for cells shape, movement, division, vesicular movement and muscle contraction. They are structured in globular actin subunits, these filaments are 7nm in diameter which are twisted into chains, they are cross-linked bundles and networks which can change. The rearrangement of these within cells is the molecular basis for change in cell shape and movement.

66
Q

Intermediate Filaments

A

These are 10nm in diameter. These are made up of subunits from a heterogenous family of proteins collectively called intermediate proteins, they are twisted together into rope-like structure, these are the toughest of cytoskeletal components. These are found in most animal cell cytoplasm network surrounding the nucleus and extending into the cell periphery and in the nucleus making up the nuclear lamina which strengthens the nuclear envelope, it is mesh-like and has attachment sites for chromatin.

67
Q

Microtubules

A

These are 25nm in diameter and are found in all eukaryotic cells. These are made up of subunits of tubulin proteins with dimers of alpha and beta tubulin, the dimers stack into filaments which form walls of stiff hollow tubes. They function for intracellular organisation, transport, mitosis, cilia and flagella. These are extended from an organising structure e.g. centrosome, spindle pole and/or basal body.

SCIE1106 (5 decks)

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