Brainscape's Knowledge GenomeTM

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


See full index

UWorld > Biochem > Flashcards

Biochem Flashcards

1
Q

What carbohydrate metabolism disorder has no symptoms but will have a positive reducing sugar urine test

A

essential fructosuria (fructokinase deficiency)

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

What does riboflavin become, making it useful energy pathways

A

FMN

FAD

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

What type of receptor is the Calcium sensing receptor that regulates PTH

A

Gq protein coupled

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

Northern blots detect target ____ in a sample

A

mRNA

can be used to assess the degree of gene transcription

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

pneumonic for what each blot (northern , western, southern) detects

A

SNoW DRoP

DNA, RNA, protein

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

In prolonged fasting, what 3 hormones upregulate gluconeogenesis

A

cortisol
epinephrine
glucagon

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

Lactate dehydrogenase is required in order for anaerobic glycolysis to occur. Why

A

it generates NAD+ which is needed in G3P –> 1,3 BPG

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

Inclusion cell (I-cell) disease is a defect in what process?

A

posttranslational modification in the Golgi
normally proteins designated for lysosomes are tagged with mannose-6-phosphate therefore lysosomal acid hydrolases with be inappropriately transported to the extracellular space

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

Gq activation –> ____ activation –> IP3 and DAG –> activation of _____

A

phospholipase C

protein kinase C

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

What is the difference between proteins translated on free ribosomes vs ribosomes attached to the RER

A

free/cytosolic ribosomes: synthesize proteins found in the cytosol, nucleosol, peroxisome matrix and nuclear encoded mitochondrial proteins
RER: synthesize most secretory proteins, integral membrane proteins of nucleus and cell membranes, and proteins within the ER, Golgi, and lysosomes

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

In pyruvate dehydrogenase deficiency, increase in what amino acids is helpful?

A

lysine
leucine
(also high fat diet)

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

Proteins tagged with mannose-6-phosphate are ultimately transported to the _____

A

lysosome

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

gait instability, scaly erythematous skin lesions in sun exposed areas, cerebellar ataxia, increased levels of urine neutral amino acids is due to what disease and what vitamin deficiency

A

Hartnup

niacin

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

Intracellular receptors that bin ___, ____, and _____ act directly as transcription factors and contain zinc-finger binding domains

A

steroids
thyroid hormone
fat soluble vitamins

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

What dietary restrictions will lead to improved symptoms of aldolase B deficiency

A

fructose and sucrose (turned into fructose)

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

Ethanol metabolism causes increased ___ which inhibits what pathway leading to hypoglycemia

A

NADH

gluconeogenesis

17
Q

what would be the cause of fever, uticarial rash and arthralgia 1-2 weeks after receiving polyvalent Fab antivenom treatment for a snake bite

A

serum sickness: type III hypersensitivity reaction due to IgG binding antivenom (made from plasma of venom-inoculated animals) and creating immune complexes which can overwhelm complement and macrophage clearing

18
Q

A purpuric rash, arthralgia, and signs of renal disease (hypertension, proteinuria) indicate what diagnosis

A

Henoch-schonlein purpura

19
Q

what is pathophysiology of henoch schonlein purpura

A

type III hypersensitivity reaction: depositions of IgA complexes triggers complement activation and inflammation of small vessels

20
Q

what are histological findings in a patient with henoch schonlein purpura

A

leukocytoclastic vasculitis: superficial blood vessels are damaged by perivascular neutrophilic inflammation, resulting in fibrin deposition in the vessel wall (fibrinoid necrosis) and red blood cell extravastation and perivascular nuclear debris from neutrophil breakdown

21
Q

What medication reduces inflammation by binding to a cytosolic receptor, translocating into the nucleus, and inhibiting proinflammatory transcription factors such as NF-kappaB

A

glucocorticoids (budesonide)

22
Q

MOA budesonide

A

glucocorticoid

23
Q

Tuberculin skin testing triggers type IV delayed-hypersensitivity reaction which is mediated by antigen recognition by APC with costimulation by APC ____ interacting with T cell ____

A

APC: CD80/86
Tcell: CD28

24
Q

At normal physiologic conditions, which are high and which are low intracellularly relative to their outer cellular concentrations: K, Na, Cl

A

high intercellular: K

Low intercellular: Na, Cl-

25
Q

Supplementation of ____ can reduce symptoms in uridine 5’-monophosphate synthesis (UMP) synthase deficiency

A

uridine

26
Q

What is defective that causes Ehlers Danlos

A

collagen synthesis

27
Q

Malignant epithelial cells in melanoma show decreased integrin expression which likely means they have decreased adherence to what component of the ECM

A

fibronectin

28
Q

Essential fructosuria is benign due to the compensatory actions of what enzyme

A

hexokinase

converts fructose to F-6-P which can be converted to glucose or pyruvate

29
Q

What is the most abundant amino acid in collagen?

A

glycine

30
Q

What are the 2 major sources of glucose during prolonged fasting? what predominates the first 12-28 hours and what predominates after that?

A

first 12-18 hours: glycogenolysis

then gluconeogensis

31
Q

How does NF kappa B become activated in the presence of bacteria

A

bacterial antigen binds toll like receptor ==> activation of IkB kindase —> ubiquitination and destruction of IkappaB –> NF kappa B is free and enters nucleus to promote synthesis of inflammatory proteins

32
Q

Describe “anaplastic” tumors

A

undifferentiated, bear no resemblance to the tissue of origin
composed of pleomorphic cells with large, hyperchromatic nuclei that grow in a disorganized fashion. They may contain numerous, abnormal mitoses and giant tumor cells

33
Q 
Which of the following are tumor suppressor genes and which are proto-oncogenes: APC
BRCA1
KRAS
RB
TP53
A

all are tumor suppressors except KRAS

34
Q

Osteosarcomas typically arise from mesenchymal stem cells that develop mutations in what genes

A

RB1 and TP53

35
Q

Ras is active when bound to what? What does Ras activate?

A

GTP

RAF (which causes a kinase cascade resulting in MAP kinase activity)

36
Q

What movement of what ions contributes the resting potential of membranes

A

high potassium efflux and some sodium influx

UWorld (19 decks)

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