Brainscape's Knowledge GenomeTM

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


See full index

Cambridge Bio Content > Cells + membranes > Flashcards

Cells + membranes Flashcards

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

What is the role of the inner membrane of the nuclear envelope?

A

The inner membrane contains lamins that bind to histones and DNA to control cell division by interacting with chromatin.

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

What is the function of nuclear pores?

A

Nuclear pores are proteins that allow the movement of substances in and out of the nucleus via special transporters.

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

What is the function of the nucleolus?

A

The nucleolus is the site of rRNA synthesis, which is combined with proteins to produce ribosomes.

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

What is chromatin?

A

Chromatin is a diffuse network of DNA bonded to histone proteins, with euchromatin (loose) and heterochromatin (tightly bound) forms.

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

What is the function of the nucleus?

A

involved in DNA replication and transcription for protein synthesis.

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

What is the structure and function of the rough endoplasmic reticulum (RER)?

A

The rough endoplasmic reticulum is a continuous membrane surrounding the nucleus, with ribosomes on the outer membrane. It is the site of protein synthesis- mRNA binds to ribosomes for translation, protein folding, glycosylation (enzymes activating proteins to add residues), and packaging proteins into vesicles, creates tertiary and quaternary structure of proteins.

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

What do secretory cells have in terms of rough endoplasmic reticulum?

A

Secretory cells have a large rough endoplasmic reticulum (RER).

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

What is the function of the smooth endoplasmic reticulum (SER)?

A

The smooth endoplasmic reticulum synthesizes lipids using enzymes (e.g., fatty acids, phospholipids, steroid hormones), detoxifies substances (e.g., alcohol) using CYP50 enzymes in liver cells, and stores and releases calcium in muscle cells in sarcoplasmic reticulum, enzymes which convert glycogen into glucose.

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

What is the function of the Golgi apparatus?

A

The Golgi apparatus modifies proteins (e.g., adding sugar molecules, phosphorylation of proteins), packages proteins into vesicles for further use, and orients certain receptor proteins for proper placement in the cell membrane. Vesicles fuse to cis Golgi and leave through trans Golgi. PROMINENT IN SECRETORY CELLS

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

What is the function of the cell membrane?

A

The cell membrane is a partially permeable membrane that controls the movement of substances in and out of the cell.

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

How does the fluidity of the cell membrane change with temperature and fatty acids?

A

The membrane becomes less fluid when there is an increased proportion of saturated fatty acids and lower temperatures, causing close packing.

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

What happens when membrane proteins denature?

A

Denaturation of membrane proteins is irreversible but changes in membrane fluidity is reversible.

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

How do organic solvents affect the cell membrane?

A

Organic solvents can dissolve lipids, increasing membrane permeability.

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

What are the components of the phospholipid bilayer in the cell membrane?

A

The phospholipid bilayer consists of hydrophilic phosphate heads and hydrophobic fatty acid tails, allowing fat-soluble molecules to pass through. This layer can be chemically modified to begin enzyme cascade and hydrolysed to produce smaller water soluble molecules that bind to receptors in cytoplasm.

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

What is the role of cholesterol in the cell membrane?

A

Cholesterol controls membrane fluidity—more cholesterol decreases fluidity and prevents freezing.

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

What are the functions of membrane proteins?

A

Membrane proteins include carrier proteins, protein channels, signaling proteins, and receptors, which facilitate transport, signaling, and cell communication.(peripheral proteins)

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

What are glycoproteins and what is their function?

A

Glycoproteins are proteins with carbohydrate groups, and they function in cell recognition, as antigens, and as receptors for hormones and neurotransmitters.

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

What are glycolipids and their function?

A

Glycolipids help in the binding of cells into tissues.

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

What is the function of lysosomes?

A

Lysosomes contain hydrolytic enzymes that break down macromolecules, worn-out organelles by forming vesicles around them (autophagy) to recycle components, and aid in cell destruction by bursting (autolysis/apoptosis).

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

What is the function of peroxisomes?

A

Peroxisomes contain catalase to prevent free radical accumulation (can cause dangerous chain reactions and bind to proteins) and oxidases for fatty acid metabolism to form acetyl choline to make lipids, ethanol breakdown, and cholesterol for plasmalogen synthesis for white matter brain cells for myelin.

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

What are the components of the mitochondria?

A

Mitochondria have an outer membrane (smooth, permeable, lots of transport proteins), cristae (folded inner membrane with ATP synthase, site of electron transport chain, less permeable), an intermembrane space (high H+ concentration), and a matrix where metabolic reactions occur.

22
Q

What is the function of the mitochondria?

A

Mitochondria are the site of ATP synthesis (via electron transport chain in oxidative phosphorylation), and they are involved in metabolic reactions such as the Krebs cycle, glycolysis, urea cycle, and ketogenesis, haem synthesis

23
Q

What is mitochondrial DNA and its role?

A

Mitochondrial DNA is inherited maternally and encodes small proteins required for metabolic reactions.

24
Q

What are ribosomes composed of?

A

Ribosomes are composed of a large subunit (60S- site of translation as it holds tRNA in place and contains condensation enzymes to catalyse formation of peptide bonds) and a small subunit (40S), made of rRNA and proteins.

25
Q

What is the function of ribosomes and where are they found in the cell?

A

Ribosomes are the site of protein synthesis (translation), using mRNA and tRNA. Found on ReR or in cytosol (make enzymes used for metabolic reactions in cell)

26
Q

What are the components of the cytoskeleton?

A

The cytoskeleton includes microfilaments (actin), intermediate filaments, and microtubules (tubulin).

27
Q

What is the role of microfilaments in the cytoskeleton?

A

Microfilaments (actin) are involved in muscle contraction, cytokinesis by forming a constriction ring, diapedesis to change shape of cell to take in pathogens, and phagocytosis.

28
Q

What is the function of intermediate filaments in the cytoskeleton?

A

Intermediate filaments anchor cells to tissue fluid, connect cells in tissues, and hold organelles in place. They are tough

29
Q

What is the role of microtubules in the cytoskeleton?

A

Microtubules provide intracellular transport through motor proteins (active process), are involved in cell division (separating chromatids), and form cilia and flagella for cell extensions

30
Q

What is the structure and function of centrioles?

A

Centrioles occur in pairs, perpendicular to each other, and move apart during cell division to form the spindle of microtubules.

31
Q

What is an electron microscope used for in viewing ultrastucture?

A

An electron microscope can be used for high-resolution imaging of cell structures, but only thin specimens can be used, and live specimens cannot be analyzed.

32
Q

How can radioactively labeled chemicals be used to study cells?

A

Radioactively labeled chemicals can be used to track where substances appear in cells.

33
Q

What is cell fractionation?

A

Homogenisation: breaking up cells by slowing enzyme action with freezing isotonic buffer solution to prevent lysis or denaturation of organelles
Filtration: through gauze to remove large debris
Ultracentrifugation: to separate cell components by density for analysis. First spun at low speeds to settle larger pellet debris and leaves solution of smaller organelles (supernatant)

34
Q

What are artefacts in microscopy?

A

Artefacts are errors caused by the specimen preparation process that can lead to inaccurate representations of cell structures.

35
Q

What is the structure of skeletal muscle cells?

A

Skeletal muscle cells fuse together during development to form multinucleate cells that contract in unison.

36
Q

What is the structure of erythrocytes (red blood cells)?

A

Erythrocytes have a biconcave shape for increased surface area, contain hemoglobin, and lack a nucleus to maximize space for hemoglobin, elastic membranes for flexibility through vessels

37
Q

What is the structure of neutrophils?

A

Neutrophils are flexible with pseudopodia (cytoplasmic projections) for engulfing pathogens, and they contain a large number of lysosomes + phagosomes and a lobed nucleus.

38
Q

What is the structure and function of sperm cells?

A

Sperm cells are haploid, contain an acrosome, mitochondria, and a rotating flagellum for movement.

39
Q

What is the function of ciliated epithelium?

A

Ciliated epithelium has cilia that move mucus and pathogens away, and goblet cells that secrete mucus to trap dust and pathogens.

40
Q

What is the structure of squamous epithelium?

A

Squamous epithelium is a thin permeable layer of cells that provides an outer covering and reduces diffusion distance. Basement membrane made up of proteins and polysaccharides.

41
Q

What is the function of epithelial cells in the ileum?

A

Epithelial cells in the ileum have microvilli to increase surface area for diffusion and a continuous blood supply to maintain concentration gradients.

42
Q

What is the role of kidney cells?

A

Kidney cells have a high number of aquaporins (channel proteins) to enable selective reabsorption of water into the body.

43
Q

What is the function of neurones?

A

Neurons have channel proteins for the movement of sodium, potassium, and calcium ions.

44
Q

What is the structure of prokaryotic cells?

A

Prokaryotic cells lack a nucleus and membrane-bound organelles, and they include a cell wall made of peptidoglycan (polysaccharides with short peptide cross linkages). Hypertonic to medium.

45
Q

What is the difference between Gram-positive and Gram-negative bacteria?

A

Gram-positive bacteria have a thick peptidoglycan layer and technic and retain the violet stain (crystal violet-iodine complex trapped in net like structure), while Gram-negative bacteria have a thin peptidoglycan layer no techoic acid and outer layer made up of lipopolysaccharides- dissolved by ethanol and take up the red counterstain.

46
Q

What is the role of the slime capsule in bacteria?

A

The slime capsule is made up of gelatine, protein and glycolipid + protects bacteria from phagocytosis, helps them adhere to surfaces, and prevents immune system identification by covering cell markers.

47
Q

What are pili and flagella used for in bacteria?

A

Pili and flagella are protein projections used for attachment to host cells, movement, and sexual reproduction in bacteria. Bacteriophages may use them as an entry point into cell

48
Q

What are plasmids in bacteria?

A

Plasmids are small circular DNA molecules that code for specific phenotypes, such as antibiotic resistance, and can replicate independently of the nucleoid.

49
Q

What are antibiotics like beta-lactams, glycopeptides, and polypeptides used for?

A

Beta-lactams (penicillin) inhibit the formation of the peptidoglycan layer in Gram-positive bacteria, glycopeptides (vancomycin) target Gram-positive bacteria even with resistance, and polypeptides (polymyxins) interact with the phospholipids of Gram-negative bacteria, often with serious side effects.

50
Q

Nucleoid in bacteria?

A

Single length or DNA not associated with histone proteins

51
Q

Ribosomes in Bacterial cells?

A

70s. Carry out protein synthesis and can be attached to plasma membrane

Cambridge Bio Content (7 decks)

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