Biochem crossword




1. A pocket or a cleft

2. Maximal velocity

3. Removal of water

4. S shaped curve

5. Covalent bond formed between the alpha amino group and the alpha carboxyl group

6. Smallest unit that is capable of performing life functions

7. Change in the optical rotation that occurs by epimerization

8. Two sugars that differ only in the configuration around one carbon atom

9. Common description of denaturation

10. Five membered ring

11. Each of two or more enzymes with identical function but different structure

12. Apoenzyme + cofactor

13. Has an aldehyde group

14. Reaction between a aldehyde and an alcohol

15. pH at which Amino acid would not move in an electric field

16. A substance that diminishes the velocity of an enzyme catalyzed reaction


1. Inactive protein part

3. Have the same number of atoms arranged differently in space

6. Hydrates of carbon whose main role is to provide energy

12. When the substrate itself serves as an effector

14. Reaction between a ketone and an alcohol

17. Highest arrangement of atoms that is in the intermediate structure between reactants and product

18. A non-protein compound necessary for the functioning of an enzyme.

19. Enzymes that are composed of more than one sub-units

20. Has a keto group

21. One of two stereoisomers of a cyclic saccharide that differs only in its configuration at the hemiacetal or hemiketal carbon

22. Six membered ring

23. The amount of energy that is needed to convert all the molecules in one mole of a reacting substance from a ground state to the transition state.

24. A monosaccharide sugar that contains four carbons

25. Michaelis constant

26. Biological catalyst that speed up a chemical reaction by providing an alternate pathway with a lower activation energy

27. Vo = Vmax / Km + [S]

28. A molecule or ion having separate positively and negatively charged groups

29. A molecule that cannot be synthesized by the body and is obtained from the diet

30. Dynamic Equilibrum

31. A covalent bond that joins a sugar molecule to another sugar

32. 1 / micrometer per minute



Test Your Knowledge ……. TCA….


1. Name the enzyme found in the Kreb Cycle (TCA) that is similar to pyruvate dehydrogenase.

(A) Alpha-ketoglutarate Dehydrogenase

(B) NADH Dehydrogenase

(C) Coenzyme A

(D) Malate Dehydrogenase

(E) Fumarase


What is the correct order os step 1 in the Kreb Cycle

1. S-citryl CoA undergoes hydrolysis to from citrate

2. An enzyme removes a proton from the CH3 in CoA

3. This causes a strong forward reaction.

4. The negatively charged CH2 bond to the oxaloacetate carbon


(A) 1, 2, 3, 4

(B) 2, 1, 3, 4

(C) 3,1,4, 2,

(D) 2, 4, 1, 3

(E) 4, 2, 3, 1


Ah Riddle Ah Riddle Ah Ree… ETC Quiz


1. Why does ATP synthase undergo conformational changes in the electron transport chain?

1. To generate ATP from ADP + P

2. To move protons from the inter-membrane to the matrix of the mitochondria

3. To move protons from the inter-membrane to the outer membrane

4. To generate ADP + P using ATP


(A) 1 only

(B) 1, 2,

(C) 2, 3

(D) 2, 4

(E) All of the above


2. Rotenone is an inhibitor that disrupts the electron transport chain complexes. Which of the complex is disrupted?

(A) Complex 1

(B) Complex 2

(C) Complex 3

(D) Complex 4

(E) ATP Synthase Complex


GLYCOLYSIS — Quiz time


1.  Which of the enzyme(s) are irreversible in the prepatory phase?

1..Phosphohexose Isomerase
2. Hexokinase
3. Aldose
4. Phosohofructo-kinase 1

(A) 1 only

(B)  1, 2

(C)  1, 3

(D)  2, 4

(E)   3, 4

2. In glycolysis process, the step(s) that produces ATP is called…

(A)  First priming reaction

(B)  Oxidative phosphorylation

(C)  Substrate level phosphorylation

(D)  Oxidation

(E)  Reductive phosphorylation

Enzyme Quiz


1. Which of the following best describes enzymes?

(A) Enzymes are biological catalysts that speed up a chemical reaction by providing and alternative pathway with lower activation energy.

(B) Enzymes are only proteins and usually it speeds up the rate of a reaction when required by the body.

(C) Enzymes are large biological molecules responsible for the thousands of chemical reactions for life sustenance.

(D) Enzymes influence chemical reactions in living systems by affecting the rate at which reactions occur

(E) Enzymes are protein catalysts that speed up a chemical reaction by lowering activation energy.

2. At high temperatures, the rate of enzyme action decreases because the increased heat

(A) changes the pH of the system

(B) alters the active site of the enzyme

(C) the reaction is in dynamic equilibrium

(D) the ratio of enzyme concentration to substrate concentration is 1:2

(E) increases the concentration of the enzyme

3. Which is true for the lock and key hypothesis?

1. substrate changes active site of the enzyme structure

2. enzyme’s active site has a complementary shape of to the substrate

3.  the functioning and role played by one enzyme is controlled by a single gene

4. R groups of the amino acids in the active site forms temporary bonds

(A) 1 only

(B) 1, 4

(C) 2, 3

(D) 2, 4

(E) All of the above

4. What defines a co-factor?

(A) organic co factors

(B) non-protein substances required by most enzymes for their efficient activity

(C) assist in the formation of the enzyme-substrate complex

(D) an unstable structure intermediate between the reactants and the products

(E)  hold substrate in a correct orientation for it to react with the active site

5. Competitive inhibition….

(A)  Binds at different sites on the enzyme not the active site

(B)   Only binds to the enzyme-substrate complex away from the active site

(C)   Binds to the active site only

(D)  Binds at a separate site from the active site

(E)   Km maybe increased or decreased

Protein Quiz

hey guys now that we have completed proteins…..its quiz time 😀


hit it your best shot

1. How many different types of amino acid are used to make proteins?

a. 4

b. 20

c. 25

d. 40

e. 100

2. Amino acids are made up of several elements carbon, hydrogen, oxygen, ………

a. Nitrogen

b. Phosphorous, Magnesium and Sulphur

c. Phosphorous, Iron and Magnesium

d. Iron and Magnesium

e. Nitrogen and Sulphur



3. Which of these is not a globular protein?

a. The skin protein collagen

b. The hormone insulin

c. The enzyme amylase

d.  Concanavilin

e. The oxygen carrier hemoglobin

4. Disulphide bridges help to maintain which aspect of protein structure?

a. Primary structure

b. Secondary structure

c. Tertiary structure

d. Quaternary structure

e. None of the above

5. The primary structure of a protein is held together by:

a. Hydrogen bonds

b. Disulphide bonds

c. Ionic bonds

d. Glycosidic bonds

e. Peptide bonds

6. A small chain of amino acids is called a

a. Side chain

b. Peptide

c. Fatty acid

d. Muscle

e. Oligopeptide

7. Which amino acid is NOT an essential amino acid?

a. Lysine

b. Methionine

c. Aspartic Acid

d. Tryptophan

e. Valine

8. Which is true about anti parallel beta pleated sheets?

1. Strong and more stable bonds

2. Long and weak bonds

3. Polypeptide strand run in opposite direction

4. Polypeptide strand run in the same direction

a. 1 only

b. 2 only

c. 1, 2, 3

d. 1, 3

e. 3, 4

Quiz time …..Carbohydrates


Hey guys, here is a short relatively easy quiz on Carbohydrates. Please attempt and have fun!

  1. 1. Monosaccharaides, such as ribose, fructose, glucose, and mannose differ significantly in

    1. Their sweetness.
    2. The positions of their carbonyl groups.
    3. Their diastereomeric configurations.
    4. Their number of carbon atoms.

    a. 1, 2
    b. 1, 3, 4
    c. 1, 2, 4,
    d. 2, 3, 4
    e. All of the above

2. Boat and chair conformations are found

a. In pyranose sugars.

b. In furanose sugars.

c. In any sugar without axial -OH groups.

d. In any sugar without equatorial -OH groups.

e. Only in a-D-glucopyranose.

3. Which polysaccharise is used as storage in animals?

a. Amylose

b. Glycogen.

c. Keratin.

d. Cellulose

e. Starch.

4. Cellulose, a b(1->4)-linked glucose polysaccharide, differs from starch in that starch is

a. a b(1->6)-linked mannose polysaccharide

b. a b(1->6)-linked glucose polysaccharide.

c. An a(1->6)-linked glucose polysaccharide.

d. An a(1->4)-linked glucose polysaccharide.

e. An a(1->4)-linked mannose polysaccharide.

5. The glycosidic bond

1. Joins glucose and fructose to form sucrose.

2. In sucrose is hydrolyzed by bees to make honey from nectar.

3. In maltose is not hydrolyzed in “lactose intolerant” humans.

4. In lactose is hydrolyzed by human infants to make two galactose monosaccharaides.

a. 1 only
b. 1, 2
c. 1. 2, 3
d. 2, 3, 4
e. All of the above


6. Cellulose fibers resemble ___ in proteins; whereas a-amylose is similar to ___.

a. a-helices; b-sheets.

b. b-sheets; a-helices.

c. b-sheets; the hydrophobic core.

d. a-helices; b-turns.

e. b-turns; coiled-coils.

7. All of the following are carbohydrates EXCEPT:

a. starch

b. glycogen

c. chitin

d. cholesterol

e. glyceraldehyde

8. Which of the following is a simple sugar or monosaccharide?

a. Sucrose

b. Galactose

c. Maltose

d. Lactose

e. Cellulose

9. Carbon can form ___ separate bonds with other elements?

a. 1

b. 2

c. 3

d. 4

e. 5

10. Sucrose is made from two monosacchrides whose name are…..

a. Fructose and Galactose

b. Two Glucose Units

c. Glucose and Fructose

d. Dextrose and Galactose

e. Mannose and Dextrose

11. . How is glucose stored in animals?

a. As dextrose in pancreas

b. As glycogen in liver & muscles

c. As cellulose in thighs & abdominal cavity

d. As protein & cellulite in adipose tissue

e. As starch in starch granules

12. When digesting a complex carbohydrate, water is added and simple sugars are obtained through which process?

a. Photosynthesis

b. Condensation

c. Hydrolysis

d. Dehydration

e. Esterification


1. What part of the cell is responsible for breaking down and digesting things?

(a)  ribosomes

(b) lysosomes

(c)  endoplasmic reticulum

(d) vacuole

2. What part of the cell serves as the intracellular highway?

(a)   endoplasmic reticulum

(b)  golgi apparatus

(c)   cell membrane

(d)  Mitochondria

3. Which of the following would you NOT find in a bacterial cell?

(a)   DNA

(b)  cell membrane

(c)   golgi apparatus

(d)  Ribosomes

4. Which of the following is found in plant cells, but not animal cells?

(a)   cell wall

(b)  vacuole

(c)   mitochondria

(d)  endoplasmic reticulum

5. The jellylike interior of the cell is called the:

(a)   vacuole

(b)  cytoplasm

(c)   cytoskeleton

(d)  nucleus

6. What part of the cell makes proteins?

(a)   ribosomes

(b)  mitochondria

(c)   lysosomes

(d)  vacuole

7. Where are ribosomes usually located in animal and plant cells?

(a)   inside the nucleus

(b)  near the cell membrane

(c)   on the endoplasmic reticulum

(d)  inside the vacuole

8. What part of the cell serves to process, package and export proteins?

(a)   mitochondria

(b)  endoplasmic reticulum

(c)   nucleolus

(d)  golgi apparatus

9. Who was the first person to see cells under the microscope and give them a name?

(a)  Anton van Leeuwenhoek

(b) Robert Hooke

(c)  Theodor Schwann

(d) Matthias Schleiden

10. He discovered that all plants were made of cells, which contributed to the development of the cell theory:

(a)  Anton van Leeuwenhoek

(b) Robert Hooke

(c)  Theodor Schwann

(d) Matthias Schleiden

11. He advanced the cell theory with his conclusion that cells could only come from other cells:

(a)  Anton van Leeuwenhoek

(b) Rudolph Virchow

(c)  Theodor Schwann

(d) Robert Hooke

12. This structure serves as the outer boundary of the eukaryotic cell:

(a)  flagella

(b) cytoskeleton

(c)  cell membrane

(d) capsule

13. Unlike eukaryotes, prokaryotes do not have:

(a)  DNA

(b) cytoplasm

(c)  cell walls

(d) a membrane bound nucleus

14. The cell theory states….

1. All life forms are made from one or more cells.

2. Cells only arise from pre-existing cells.

3. The cell is the smallest form of life

4. cells must contain DNA

(A) 1 only

(B) 2, 4

(C) 1, 2, 3

(D) 3, 4

(E) All of the above

15. The word cyto means:

(a)  cell

(b) dark

(c)  jelly

(d) small

16. Tiny structures that carry out cell functions are collectively called:

(a)  animalcules

(b) organelles

(c)  tissues

(d) ribosomes

17. Which of the following organelles is most important in providing energy to the cell?

(a)   mitochondrion

(b)  centrosome

(c)   nucleus

(d)  peroxisome

18. Name the membrane valves that open and close for potassium efflux and sodium influx.

(a)  ion channels

(b) vacuoles

(c)  capillaries

(d) cytokines

19. What organelle in higher plant cells contains chlorophyll?

(a)   chloroplasts

(b)  cytosol

(c)   secretory vesicles

(d)  nucleus

20. What is the difference between cytosol and cytoplasm?

(a)   cytosol is the intra- cellular fluid, cytoplasm is part of the cell which contains the entire cell membrane

(b)  cytoplasm  is the intra- cellular fluid, cytosol is part of the cell which contains the entire cell membrane

(c)   metabolic reactions take place in the cytoplasm and not the cytosol

(d)  cytosol is made up of 60% water, cytoplasm is made up of 40% water only

(e)  answer not given