biol 2010 midterm 2

What has an important role in cell structure, cell identity, and energy storage?

Carbohydrates

What is defined as one sugar monomers?

Monosaccharides

What is defined as few sugars and are small polymers?

Oligosaccharide

What is defined as many sugars and are large polymers?

Polysaccharides

What has the molecular formula (CH2O)n?

Carbohydrates

what is a carbohydrate made of?

Carbonyl (C=O), hydroxyl (-OH), and (C-H)

(T/F) All CH2O compounds are carbohydrates

F

What was required for nucleotide formation?

Ribose

Sugars provide ____ ____ in cells and serve as ____ ____ for larger compounds

chemical energy and building blocks

______ played n important role in chemical evolution

Monosaccharides

What affects the structure of a monosaccharide monomer?

Location of the carbonyl group and the number of carbons

A monosaccharides with the carbonyl group at the end is an ______

Aldose

A monosaccharides with the carbonyl group in the middle is a ________

Ketose

A monosaccharides with 3 carbons is a ______, five carbons is a ______, and six carbons is a _________

triose, pentose, and hexose

Sugars typically form ____ structures in aqueous solutions

Ring

How is glucose different from galactose?

Glucose’s hydroxyl group is behind plane and Galactose’s is above on carbon 4

Monosaccharides can be in which two forms?

Linear and ring

Monosaccharides can differ because of the _____ _____ of their atoms

Spatial arrangement

Each monosaccharide has a _____ structure and function

Unique

Polysaccharide are also known as _______ ______

Complex carbohydrates

Polysaccharide are polymers of _______ _______

monosaccharides monomers

Two sugars linked together form a ______

disaccharide

What causes sugars to form linkages?

Condensation reaction (loose water) between two hydroxyl groups

What is it called when two sugars linked together together using a covalent bond?

Glycosidic linkage

How can sugar linkages be broken down

Hydrolysis reaction (consume water)

Glycosidic linkages can form between two _____ groups

hydroxyl

What are the two most common glycosidic linkages?

alpha-1,4 and beta-1,4

(T/F) Both the alpha-1,4 and beta-1,4 glycosidic linkages are between the 1st and fourth carbon

T

Which glycosidic linkage requires the monomer to be flipped in order to form a link with another sugar?

beta-1,4

What do plants store sugar as?

starch

______ is composed of a-glucose monomers

starch

Starch forms a ______

helix

what are the two types of starches?

amylose and amylopectin

Which type of starch is unbranched with only alpha-1,4 glycosidic linkages?

Amylose

Which type of starch is branched and has some alpha-1,6 glycosidic linkages

Amylopectin

Starch is used for _____ _____ in plant cells

energy storage

How often do the branches occur in amylopectin?

every 30 monomers

Animals store sugar as ________

glycogen

Where do animals store sugar?

liver and muscle cells

Glycogen can be broken into ____ ____ for energy

glucose monomers

Which type of polysaccharide is nearly identical to starch?

Glycogen

Glycogen is a highly branched _______ polymer

a-glucose

How often does glycogen branches occur?

1 out of 10 monomers

What is the structural polymer found in the cell wall of plants?

Cellulose

What polysaccharide in plants is made of beta-1,4 glycosidic linkages?

Cellulose

Cellulose is a ______ molecule b/c every other glucose is flipped

linear

What is the polymer found in cell walls of fungi and exoskeletons of insects and crustaceans?

Chitin

Chitin is a ______ polymer

structural

What is the monomer that makes up chitin?

N-acetylglucosamine (NAG)

The strands of cellulose is joined by _____ bonds

hydrogen

The parallel strands of chitin is joined by ______ bonds

hydrogen

Which structural polysaccharide is similar to cellulose in terms of the linkages and every other flipped monomer?

chitin

Chitin forms _____ _____

linear strands

The is the structural polymer found in bacterial cell walls?

Peptidoglycan

Peptidoglycan is joined by ________ glycosidic linkages

beta-1,4

(T/F) Glycogen uses only alpha-1,4 linkages

F (and a-1,6)

Which polysaccharide only uses N-acetylglucosamine as its monomer?

Chitin

Which structural polysaccharide is made of the NAG (N-acetylglucosamine) and NAM (N-acetylmuramic acid) monomers?

Peptidoglycan

How is the linear strands of peptidoglycan formed

peptide bonds

_______ serve as precursors to other molecules like nucleotides and amino acids

carbohydrates

Cellulose, chitin, and peptidoglycan gives cells and organisms ______ and elasticity

strength

(T/F) Most organisms have the enzymes to hydrolyze beta-1,4 glycosidic linkages

F (they dont)

______ form dietary fiber which is important for digestive health

sugars (carbohydrates)

Why is it difficult to hydrolyze b-1,4 linkages

Lack of water

Carbohydrates indicate cell ______

indentity

What is defined as a protein with attached carbohydrates?

Glycoproteins

What is defined as lipids attached to carbohydrates?

Glycolipids

What carbs are important in cell-cell recognition and cell-cell signaling?

Glycoproteins and glycolipids

ABO blood groups are _____ on red blood cells and help will cell identity

glycolipids

________ store and provide chemical energy

carbohydrates

Plants harvest energy from sunlight and store in in the bonds of carbohydrates during _______

photosynthesis

Why do carbohydrates store more energy than CO₂?

C-H and C-C bonds are weaker and have higher potential energy (less electronegative)

Why is the beta linkage more common

more stable

What is it called when the -OH of a carb is below the plane

alpha

What is it called when the -OH of a carb is above the plane?

beta

Glycosyltrasnferase is an _____ used to speed up ____ ____

enzyme and glycosidic linkages

Which blood type involves adding n-acetylgalactosamine to the membrane lipid on red blood cell

Type A

Which blood type involves adding galactose to membrane lipid on red blood cell

Type B

Glycosyltransferases is an enzyme that helps determine ____ ___ by attaching specific sugars to the surface of certain cells

blood type

(T/F) Type O has it enzymes on it

F

Which complex carbs are easily hydrolyzed b/c they have an a-glycosidic linkage

starch and glycogen

(T/F) alpha linkages are packed more tightly than beta linkages

F (other way around)

Glycogen is hydrolyzed by the enzyme ________

phosphorylase

(T/F) many animal cells contain phosphorylase

T

Starch is hydrolyzed by _______ enzymes

amylase

Amylases play a key role in carb ______

digestion

Where are the carbohydrate portions of glycoproteins found?

exterior surface of cell membrane

Simple sugars can differ from one another b/c of the _____ ___ ____ ___

location of carbonyl group

What would the molecular formula be of six carbon disaccharide made of two trioses

C6H10O5

Carbohydrates have a variety of functions. Which polysaccharide helps fecal material move through the intestinal tract, thus preventing constipation?

Cellulose

Which cell types have the same glycoproteins on their surfaces?

none. each cell type has a different glycoprotein on its surface

Polysaccharides probably did not play an important role in the origin of life because __________.

They cannot serve as a template for replication

In the experiment investigating cell–cell recognition between egg and sperm during fertilization, what part of egg-surface glycoproteins was recognized by sperm?

Carbohydrate

Carbohydrates are made up of which of the following monomers?

monosaccharides

Which chemical formula could represent a monosaccharide?

C3H6O3

(T/F) Cell membrane and cell wall are the same thing

F

Cell membrane is also known as _______ membrane

plasma

Plasma membrane serves as a _____ _____

selective barrier

(T/F) Lipids are soluble in water

F

Lipids contain lots of _____ atoms

carbon