Brainscape's Knowledge GenomeTM

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


See full index

AA JW Science Review > KA Cells > Flashcards

KA Cells Flashcards

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

What is apposition?

A

Direct contact between the endometrium and the embryo, just before implantation.

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

Which germ layer forms the liver?

A

Endoderm

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

What are the 3 main factors that affect membrane fluidity?

A
  1. Temperature. 2. Cholesterol. 3. Level of unsaturation of phospholipids.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Describe what happens when a ligand binds to a G protein-coupled receptor.

A

The G protein-coupled receptor undergoes a conformational change. This causes the alpha subunit of the G protein to exchange GDP for GTP. Then, the alpha subunit dissociates. Now the alpha subunit is free to move through the membrane and interact with its target protein. Usually, this results in the creation of a second messenger. (The remaining beta-gamma complex can also interact with a target protein of its own, but this is less common.)

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

Which germ layer forms the testes?

A

Mesoderm

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

What are embryoblasts?

A

They are the cells that form the inner layer of the morula.

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

What does GPCR stand for?

A

G protein-coupled receptor

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

What is the difference between a channel protein and a carrier protein?

A

They are the 2 types of transport proteins. A channel protein provides a channel that a specific molecule can flow through, down its concentration gradient. A carrier protein changes shape and carries a molecule across the PM (can either be passive or active).

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

What is the primitive streak?

A

It is an indentation along the dorsal surface of the epiblast. Cells migrate through it, and then differentiate into endoderm and mesoderm. The cells that do not migrate through will become ectoderm.

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

What is the term for when a phospholipid moves from one side of the PM to the other?

A

Transbilayer diffusion, aka “flip flopping”.

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

What does RTK stand for?

A

Receptor tyrosine kinase

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

What is blastulation?

A

It is the formation of a blastula from a morula.

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

What is found in the midpiece of a sperm cell?

A

Mitochondria

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

What is the neural plate? How is it formed?

A

It is formed when the notochord induces the ectoderm to thicken into the neural plate. After it forms, the neural plate cells start to “dive” into the mesoderm and form a hollow tube called the neural tube.

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

What is the general function / purpose of an RTK?

A

Their function is to phosphorylate (and thus activate) their target protein.

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

Explain the signal transduction pathway that occurs when epinephrine binds to a target cell.

A

Epinephrine binds to an adrenergic receptor (a GPCR), causing a conformational change in the GPCR. This causes the alpha subunit to exchange GDP for GTP. Then, the alpha subunit dissociates and can bind to and activate its target protein (adenylate cyclase). This causes ATP to be turned into cAMP (second messenger), which carries out the actions of epinephrine (increased heart rate, dilate blood vessels, break down glycogen, etc).

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

Which germ layer forms the GI tract?

A

Endoderm

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

What is compaction?

A

After the morula forms, the cells start to get closer together.

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

Which germ layer forms the sweat glands?

A

Ectoderm

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

What is the role of hCG in embryogenesis?

A

hCG is secreted by the trophoblasts after implantation. hCG causes the corpus luteum to survive, enlarge, and continue producing estrogen and progesterone to suppress menses.

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

Describe G protein-coupled receptors.

A

They are only found in eukaryotes. They are involved in a huge variety of processes in the body. They have 7 transmembrane alpha helices.

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

Describe ligand-gated ion channels. What types of cells are they typically found in?

A

They are ion channels that are closed in a resting state, but open in response to the binding of a ligand. The ligand binds to an allosteric site (away from the actual channel). The ligand-binding site is almost always on the extracellular side. Some ligand-gated ion channels may have more than one binding site. Ligand-gated ion channels are typically found in neurons.

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

Describe desmosomes, and name 2 bodily locations where they are found.

A

Desmosomes connect adjacent cells with thin, filamentous proteins. They connect to the cytoskeleton on the inside of cells. They are found in areas of the body that experience physical stress, such as the skin and intestines.

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

What happens after the endometrium contacts the embryo?

A

The trophoblasts start to multiply and invade the endometrial tissue. This process is called adhesion. It ensures that the embryo gets “stuck” to the endometrium.

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

What is the ultimate fate of the trophoblasts?

A

They will become the chorionic sac and the fetal portion of the placenta.

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

What is the function of cholesterol in the plasma membrane?

A

It moderates membrane fluidity. It increases fluidity at low temperatures, and decreases fluidity at high temperatures. It can be thought of as a “fluidity buffer”.

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

What is found in the tail of a sperm cell?

A

A flagellum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Describe scramblase. What does it do?

A

It is an integral membrane protein (enzyme) that moves a phospholipid from the inner leaflet of the PM to the outer leaflet, AND moves another phospholipid from the outer leaflet to the inner leaflet. It does NOT require ATP.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Which germ layer forms the hair?

A

Ectoderm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Describe flippase. What does it do?

A

It is an integral membrane protein (enzyme) that uses ATP to move a phospholipid from the outer leaflet of the PM to the inner leaflet.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Which germ layer forms the ovaries?

A

Mesoderm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Which germ layer forms the heart?

A

Mesoderm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Which germ layer forms the epithelia of the lungs?

A

Endoderm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Describe gap junctions, and name 2 bodily locations where they are found.

A

Gap junctions form a direct connection between the cytoplasms of two adjacent cells. They are often used to transmit action potentials between cells. They are found in the heart and the nervous system (and probably other locations too).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Which germ layer forms the skeletal system?

A

Mesoderm

36
Q

What is a blastomere?

A

Each daughter cell produced by cleavage is called a blastomere.

37
Q

What are cortical granules?

A

They are granules found inside egg cells, near the PM. When a sperm reaches the egg’s PM, the granules release enzymes into the zona pellucida, which then digest the glycoprotein that allows sperm to bind. This is a block to polyspermy.

38
Q

Which germ layer forms the bladder?

A

Mesoderm

39
Q

Which germ layer forms the nails?

A

Ectoderm

40
Q

Describe the general structure of an enzyme-linked receptor.

A

They have an extracellular ligand-binding domain, a transmembrane region, and an intracellular enzymatic domain.

41
Q

Describe how the G protein cascade is turned off.

A

The alpha subunit hydrolyzes GTP (active) to GDP (inactive). This causes everything to revert back to its resting state (alpha, beta, and gamma subunits reassociate, ligand detaches from GPCR, etc).

42
Q

What are trophoblasts?

A

They are the cells that form the outer layer of the morula.

43
Q

What is neurulation?

A

It refers to the formation of the notochord. This occurs in the middle of the mesoderm, underneath where the primitive streak was.

44
Q

Name one important function of glycoproteins.

A

They are used in cell signalling. They allow the cell to be recognized by another cell.

45
Q

What is it called when a zygote divides without growth?

A

Cleavage

46
Q

What are hypoblasts?

A

They are cells derived from the embryoblasts. They contact the blastocoel.

47
Q

Which germ layer forms the nervous system?

A

Ectoderm

48
Q

Which germ layer forms the outer layers of the skin?

A

Ectoderm

49
Q

What is the zona pellucida? What does it do?

A

It is a thick layer of glycoproteins that sits on the outside of the egg. It binds to the sperm cell in the first step of fertilization.

50
Q

Describe tight junctions, and name 3 bodily locations where they are found.

A

Tight junctions form a watertight seal between adjacent cells. They are found in the bladder, the intestines, and the kidneys (and other places).

51
Q

What is the bilaminar disk?

A

It is derived from the embryoblast. It forms when the embryoblast turns into epiblasts and hypoblasts.

52
Q

What are the 3 types of endocytosis? Describe each one.

A
  1. Phagocytosis (eating. can be highly specific). 2. Pinocytosis (drinking. not very specific). 3. Receptor-mediated endocytosis (highly specific).
53
Q

What is found in the head of a sperm cell?

A

DNA, and the acrosome

54
Q

Which germ layer forms the muscular system?

A

Mesoderm

55
Q

What is gastrulation?

A

It is the formation of the 3 germ layers.

56
Q

What are epiblasts?

A

They are cells derived from the embryoblasts. They line the amniotic cavity.

57
Q

Describe the cortical reaction.

A

It starts when the sperm reaches the egg’s PM. Enzymes contained within cortical granules are exocytosed out of the egg cell, and they start to digest the zona pellucida (specifically, they digest the glycoprotein that allows sperm to bind to the ZP). This makes it so that no other sperm can bind (block to polyspermy).

58
Q

Which germ layer forms the inner layers of the skin?

A

Mesoderm

59
Q

Which germ layer forms the kidneys?

A

Mesoderm

60
Q

What are neural crest cells?

A

As the neural tube is forming, some cells are breaking off from the ectoderm and entering the mesoderm. These cells (neural crest cells) will differentiate into other tissues.

61
Q

What is the term for when a molecule that has both a hydrophobic section and a hydrophilic section?

A

Amphipathic

62
Q

What is a blastocyst?

A

An embryo that has an outer layer of trophoblasts, an inner cell mass (embryoblasts), and a blastocoel.

63
Q

What percentage of blastocysts fail to implant?

A

Around 50% - 75%

64
Q

What is a crypt?

A

A “valley” in the endometrial lining, which serves as a site for implantation.

65
Q

What is the amniotic cavity?

A

It is the second cavity that forms in the developing embryo. It forms inside the mass of embryoblasts.

66
Q

Name the 3 types of cell junctions.

A
  1. Gap junctions. 2. Tight junctions. 3. Desmosomes.
67
Q

What is a morula?

A

A zygote that has undergone cleavage, so it is composed of ~16-32 cells, but has not grown in size. Morula = Greek for mulberry (lots of little dots).

68
Q

What is the term for when a phospholipid moves around within the same side of the PM, without switching sides?

A

Lateral diffusion.

69
Q

Which germ layer forms the circulatory system?

A

Mesoderm

70
Q

Which germ layer forms the pancreas?

A

Endoderm

71
Q

Define amphipathic

A

A molecule that has both a hydrophobic section and a hydrophilic section.

72
Q

What are the steps involved in fertilization?

A
  1. Sperm binding to the zona pellucida. 2. Acrosome reaction (acrosomal enzymes are released, and start to digest the zona pellucida). 3. Cortical reaction. 4. Transfer of genetic material.
73
Q

Name the 3 main types of cell membrane receptors.

A
  1. Ligand-gated ion channels.
  2. G protein-coupled receptors.
  3. Enzyme-linked receptors.
74
Q

Name the 3 parts of a sperm cell.

A

The head, the midpiece, and the tail.

75
Q

What separates maternal blood from fetal blood?

A

A layer of trophoblasts (as this sturcture grows, it becomes the placenta).

76
Q

What happens to the trophoblasts after implantation?

A

They continue to multiply. Some of them fuse together into large, multinucleated cells (called syncitiotrophoblasts) that stick out (via villi) and contact the maternal blood pools. The rest of them remain as regular cells, and are now called cytotrophoblasts.

77
Q

What is the most common type of enzyme-linked receptor?

A

Receptor tyrosine kinase

78
Q

What are the 3 main components of the plasma membrane?

A
  1. Phospholipids. 2. Cholesterol. 3. Proteins.
79
Q

Describe G proteins.

A

They can bind to GTP and GDP (that’s why they are called G proteins). Some G proteins have only 1 subunit, but all G proteins that associate with a G protein-coupled receptor are heterotrimeric (they have 3 unique subunits - alpha, beta, and gamma). Alpha and gamma subunits attach to the PM via lipid anchors.

80
Q

Describe the structure of a RTK, and explain what happens when it binds its ligand.

A

A receptor tyrosine kinase has Tyr residues on the intracellular (enzymatic) domain. RTKs come in pairs (found nearby each other). When each subunit of the pair has bound its ligand, they associate and form a cross-linked dimer. Now the two parts of the pair can phosphorylate each other (this is called cross-phosphorylation). Once all the tyrosines in both subunits have been phosphorylated, the complex can serve as a “docking platform” for target proteins (can be multiple types), which are then phosphorylated.

81
Q

Describe floppase. What does it do?

A

It is an integral membrane protein (enzyme) that uses ATP to move a phospholipid from the inner leaflet of the PM to the outer leaflet.

82
Q

Which germ layer forms the inner layers of the lungs?

A

Endoderm

83
Q

At what point does the developing embryo move from the uterine tube into the uterus?

A

Around the time when the zygote becomes a morula (~16-32 cells).

84
Q

What is the next step in embryogenesis, after the gastrula has formed?

A

Neurulation.

85
Q

What is placental previa?

A

It is a condition in which the placenta partially or completely covers the cervix. It can occur if the embryo implants too close to the cervix.

86
Q

What is a blastocoel?

A

It is the little cavity that forms in a blastocyst (caused by continued compaction of embryoblasts).

AA JW Science Review (6 decks)

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