Molecules - Carbohydrates and Lipids P43

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What characteristic defines a monosaccharide?

Contains one hydroxyl group and a carboxyl group

Is made up of amino acids

Is a polymer of fatty acids

Has a carbon chain of 3-7 carbons with one aldehyde group (correct)

Which statement accurately describes saturated fatty acids?

They contain more hydrogen atoms compared to unsaturated fatty acids (correct)

They are characterized by having multiple carboxyl groups

They are liquid at room temperature

They have at least one double bond in their carbon chain

What is true about triglycerides?

They are primarily used as a source of immediate energy

They are formed through the process of esterification (correct)

They are always liquid at room temperature

They consist of one fatty acid and two glycerol molecules

How does the solubility of fatty acids change with the length of the carbon chain?

Long carbon chains have less solubility than shorter chains Signup and view all the answers

Which type of molecule is glycerol classified as?

A polyhydroxy compound without an aldehyde group Signup and view all the answers

What differentiates organic compounds from inorganic compounds like Carbon Dioxide?

Organic compounds only have covalent bonds such as H-C or C-C. Signup and view all the answers

Which process occurs when monomers are combined to form a polymer?

Dehydration synthesis Signup and view all the answers

What type of carbohydrates are ribose and glucose classified as?

Monosaccharides Signup and view all the answers

What happens to the valence shells of molecules during dehydration synthesis?

They empty by 1 electron. Signup and view all the answers

What is the key feature of sugar alcohols as compared to monosaccharides?

Sugar alcohols replace the carbonyl group with a hydroxyl group. Signup and view all the answers

Which of the following statements about lipids is true?

Lipids are stable compared to proteins and carbohydrates. Signup and view all the answers

How does hydrolysis differ from dehydration synthesis?

Hydrolysis adds water to break bonds, while dehydration synthesis removes water to form bonds. Signup and view all the answers

Which type of bonding is primarily responsible for the stability of lipids?

Covalent bonding Signup and view all the answers

What form does a glucose molecule take when the hydroxyl group is pointing up?

Beta glucose Signup and view all the answers

Which type of glycosidic bond occurs between glucose and fructose to form sucrose?

Alpha 1->2 Signup and view all the answers

What distinguishes amylose from amylopectin?

Amylose only has alpha 1->4 linkages; amylopectin has alpha 1->6 linkages at branching points. Signup and view all the answers

Which carbohydrate is known as the main storage form of carbohydrates in animals?

Glycogen Signup and view all the answers

What type of polymer is cellulose, and what is its primary role?

Structural component in plant cells Signup and view all the answers

Which is NOT a characteristic of monosaccharides?

They consist of long chains of glucose Signup and view all the answers

What type of bond forms between carbon 1 and carbon 4 in glycogen molecules?

Alpha 1->4 Signup and view all the answers

What primary component do both chitin and cellulose share?

Structural role in cells Signup and view all the answers

What characteristic distinguishes cis fats from trans fats?

Cis fats are bent in structure due to the positioning of hydrogen atoms. Signup and view all the answers

Which type of fatty acid is typically liquid at room temperature?

Oleic acid Signup and view all the answers

What component distinguishes phospholipids from triglycerides?

Phospholipids have a phosphate group replacing one fatty acid. Signup and view all the answers

How does the presence of unsaturated tails affect phospholipid packing density?

It reduces the number of molecules that can pack in the same space. Signup and view all the answers

Which type of lipid is responsible for forming signaling molecules such as testosterone and estradiol?

Steroids Signup and view all the answers

What role do glycolipids play in biological systems?

They are crucial for immune response. Signup and view all the answers

What structure do phospholipids spontaneously form in an aqueous environment?

Bi-layer Signup and view all the answers

What type of bond is primarily formed between the glycerol backbone and fatty acids in triglycerides?

Ester bond Signup and view all the answers

What is the primary factor determining the physical state of a fatty acid (solid or liquid) at room temperature?

The saturation level of the fatty acid. Signup and view all the answers

Which lipid is made from a lipid chain of alkanes and is known for being hydrophobic?

Waxes Signup and view all the answers

Study Notes

Molecules Overview

Four primary types of biological molecules:
- Carbohydrates (CHO)
- Lipids (CHOP)
- Proteins (CHONS)
- Nucleic acids (CHONP)
Cells are predominantly composed of water, which serves as a medium for biochemical reactions.
Carbohydrates and proteins show variability depending on the cell type, while lipids maintain more consistency.

Organic vs. Inorganic Compounds

Carbon Dioxide (CO2) is considered inorganic due to the absence of covalent H-C or C-C bonds.
Structural diagrams like skeletal formulas represent carbon atoms at line ends and vertices.

Polymer Formation

Monomers combine to form polymers via dehydration reactions, removing water to form covalent bonds.
Hydrolysis is the reverse process, adding water to break down polymers into monomers.
Branching is possible in polymers, facilitating energy storage.

Carbohydrates

Types of carbohydrates:
- Monosaccharides (e.g., glucose, fructose)
- Disaccharides (e.g., sucrose formed from glucose and fructose)
- Oligosaccharides
- Polysaccharides (e.g., glycogen, starch)
Monosaccharides are polyhydroxy aldehydes or ketones and often exist in ring structures, particularly 5 or 6-membered rings.
Alpha and beta glucose are isomers distinguished by the orientation of the hydroxyl group.

Polysaccharide Characteristics

Glycogen serves as short-term carbohydrate storage in animals (found in liver and muscles) and consists of alpha 1-4 and alpha 1-6 linkages.
Starch, the plant storage form of glucose, has two types:
- Amylose: linear structure (alpha 1-4)
- Amylopectin: branched structure (alpha 1-6 branching)
Cellulose is the most abundant natural polymer, providing structural support in plants, and is indigestible.
Chitin, a structural component in exoskeletons and fungal cell walls, is composed of N-acetylglucosamine (NAG) units.

Lipids

Lipids are organic molecules that are non-polar and insoluble in water.
Key types of lipids include fatty acids, triglycerides, phospholipids, steroids, waxes, and glycolipids.
Fatty acids can be saturated (no double bonds) or unsaturated (one or more double bonds).
Triglycerides consist of glycerol and three fatty acids, serving as the main form of energy storage.

Fat and Oil Properties

Fats are saturated, solid at room temperature, and have higher melting points (e.g., butter).
Oils are liquid at room temperature due to the presence of unsaturated fatty acids.
Cis isomers have bent structures, while trans isomers are straight due to the positioning of hydrogen atoms.

Phospholipids

Phospholipids contain a hydrophilic phosphate head and hydrophobic fatty acid tails, forming bilayers in aqueous environments essential for cell membranes.
Their structure influences fluidity; unsaturated tails result in lower melting points and greater fluidity.

Steroids and Other Lipids

Steroids, such as cholesterol, play critical roles in signaling (e.g., testosterone, estradiol).
Waxes are hydrophobic lipids used by organisms for protection against dehydration.
Glycolipids consist of sugars, glycerol, and fatty acids, crucial for immune responses and blood type differentiation.

Lipopolysaccharides

Found in the cell walls of some bacteria, providing structural integrity and protection.
Lipid A is linked to pathogenicity through its sugar components, which face the external environment.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

This quiz focuses on the structural aspects of molecules, specifically carbohydrates and lipids, as detailed on page 43. You will explore concepts such as the composition of carbohydrates, lipids, and other biological molecules, including their stability and variation in different cells. Test your understanding of organic versus inorganic compounds.