BIO FLASHCARDS #2: Carbon, Protein, & Carbohydrates

Geet Patel

How many covalent bonds do carbons have?

4

Isomers?

•Have the same number of atoms of the same elements but different structures

•Different structures means different properties!

Ex]

a) structural isomers

b) cis isomer- the two x are on the same side

c) trans isomers- the two x are on opposite sides

d) enantiomers- mirror images

8 Functional groups?

*Be able to draw!

1. Hydroxyl -OH

2. Carbonyl C=O

3. Carboxyl COOH

4. Amino -NH₂

5. Sulfhydryl -SH

6. Phosphate -PO₄^2-

7. Methyl -CH3

What are the 4 major biological molecules?

´Carbohydrates

´Lipids

´Proteins

´Nucleic Acids

polymer

• a larger molecule made by joining many smaller units

• ex] In carbohydrates: glucose + glucose + glucose= polysaccharide

monomer

• a small molecular unit that can be joined to other monomers to make a larger molecule (building block)

• for carbohydrates, individual sugar molecules can act as building blocks.

• Ex] glue → one sugar unit

dehydration synthesis

• Dehydration synthesis is a reaction that joins molecules toghther while removing water

• the molecules are being built toghther

• small molecules called monomers, join toghther to form larger molecules called polymers, by releasing a molecule of water.

• connect simple sugar molecules

hydrolysis?

• breaks a larger molecule apart by adding water

• during the process, water splits into a hydrogen ion and a hydroxyl group while attach a new seperated parts of the original molecule

• (water enters molecule breaks)

• breaks glucose bonds holding complex CH together

Monosaccharide?

• a carbohydrate made of 1 sugar unit

• major nutrients of cells used for energy and building blocks for other molecules

• Glucose breaks down during cellular respiration to make ATP

• Ex] glucose and fructose

Disaccharides?

• 2 sugars joined together

• Sucrose: plants transport carbohydrates from leaves to roots

• Lactose: (milk sugar)

• Sucrose: One glucose unit plus one fructose unit (table sugar).

• Lactose: One glucose unit plus one galactose unit (milk sugar).

• Energy Source: The body breaks them down into single sugars to power cells.

• Nutrient Supply: Milk sugar gives vital food and energy to baby mammals.

• Plant Transport: Plants move food energy through their stems using double sugars

Oligosaccharides?

• a few sugars

• Cell surface glycan

• Human milk oligosaccharides:

Cell-surface glycans

• a molecular identification label

• Cell-surface glycans are sugar groups attached to molecules on the surface of the cells

• CSG ARE IMPORTANT FOR: cell to cell recongniton and communication

• Sugar groups attached to molecules on the cell surface

HMOs?

• found in human breast milk

• evolved to feed beneficial bacteria

• humans don’t make an enzyme to recognize them

• supports beneficial microbes

What is a Polysaccharides?

Polysaccharides are complex carbohydrates made of long chains of simple sugar molecules linked together.

4 examples and functions of polysaccharides.

1. Starch: energy storage in plants

´Polymer of glucose

´How plants store sugar reserves

´Stored in plastids of plant cells

2, Glycogen: energy storage in animals

•Polymer of glucose

•How animals store sugar reserves

•In vertebrates, found mainly in liver cells and muscle cell

3. Cellulose: structural support in cell wall plants´Polymer of glucose

´Major structural component of the plant cell wall

´Part of “insoluble fiber” in human diet

´Cow solution?

´Termite solution?

4. Chitin: strutural support in fungi and arthropods

´Used to build exoskeletons of arthropods

´Fungi use to build their cell wall

Give two examples of symbiotic relationships involving carbohydrates, animals, and microbes

1. Humans + beneficial bacteria

• microbes use HMO as food source

2. Cows + microbes

• plants have lots of cellulose

• cellulose i hard for animals to digest

• microbes in the cows digestive system help break down plant material

• cows obtain nutrients

3. Termites + Microbes

• consume wood, which has cellulose

• animal gets help by obtained nutrients

ALL MUTUALISM

Molecular structure of a carbohydrate

To recognize a carbohydrate by its molecular structure, look for a carbon chain bound to hydrogen and oxygen in a 1:2:1 ratio,(C_n(H₂O)_n), containing multiple hydroxyl groups (-OH) and an internal carbonyl group (C=O) that forms either an open chain or a ring.

Name all 8 important proteins!

1. Enzyme

2. Storage proteins

3. hormonal proteins

4. contractile and motor proteins

5. defensive proteins

6. transport proteins

7. receptor protein

8. structural protein

Enzymatic protein?

function: selective acceleration of chemical reactions

example: digestive enzyme catalyze the hydrolysis of bonds in food molecules.

Storage proteins?

Function: Storage of amino acids

Examples: Casein, the protein oof milk, is a major source of amino acids for baby mammals. Plants have a storage protein in their seeds.

• Ovalbumin is the protein of egg while, used as an amino acid source for the developing embryo

Why are things for baby plants and animals so rich in storage proteins?

• Baby plants (seeds) and animals (eggs and milk) need a dense and easy-to-use source of food and building blocks to grow before they can find or make their own food. Storage proteins hold large amounts of nitrogen, carbon, and amino acids in a small space.

Hormonal Proteins?

Function: Coordination of an organism’s activities

Example: Insulin, a hormone secreted by the pancreas, causesother tissues to take up glucose thus regulating blood sugar concentration.

contractile and motor proteins

Function: Movement

Examples: Motor proteins are responsible for the undulations of cilia and flagella. Actin and myosin proteins are responsible for the contraction of muscles

What do the actin and myosin do?

• Actin and myosin are the two main protein filaments that work together to make muscles contract and move.

• Thick myosin filaments pull on thin actin filaments, sliding past each other to shorten the muscle cell in a process powered by energy from ATP

• Tears in muscles causes soreness after new exercise.

Defensive proteins?

Function: Protection against disease

Example: Antibodies inactivate and help destroy viruses and bacteria

what is an antigen?

An antigen is any substance, such as a protein or sugar, that makes your body start an immune response

transport proteins

Function: Transport of substances

Examples: Hemoglobin, the iron-containing protein of vertebrate blood, transports oxygen from the lungs to other parts of the body. Other proteins transport molecules across cell membranes

Receptor Proteins?

Type of Cells

• Neurons: The cells shown in the diagrams are nerve cells (neurons).

• Presynaptic Cell: The neuron transmitting the signal.

• Postsynaptic Cell: The neuron receiving the signal.

Name of Signaling Molecules

• Neurotransmitters: The chemical signaling molecules released into the synaptic cleft.

Relation to "Mouse Party"

• Both the diagrams and the "Mouse Party" animation depict how neurons communicate at a synapse.

• The signaling molecules cross the gap and bind to specific receptor proteins on the postsynaptic membrane.

• The "Mouse Party" animation specifically shows how different drugs (like THC, ecstasy, or cocaine) alter this exact mechanism by blocking, mimicking, or overstimulating these receptor proteins and neurotransmitters (such as dopamine and serotonin).

Structural proteins?

Amino Acids?

• Monomers that build proteins

• 20 different amino acids make up all living things

• BE ABLE TO DRAW

The properties of R groups….

Properties of R groups give amino acids and their proteins different properties.

answer?

• The images demonstrate that changing a single amino acid's R-group can drastically alter a protein's structure and function, leading to physiological diseases like sickle cell anemia.

• Glutamic Acid: Possesses a hydrophilic (polar/charged) R-group. It interacts favorably with water on the exterior of normal hemoglobin molecules. This keeps red blood cells flexible and disc-shaped.

• Valine: Possesses a hydrophobic (nonpolar) R-group. When it replaces glutamic acid, it avoids water and seeks out other hydrophobic regions.

Be able to identify a peptide bond!

Primary Structure of a Polypeptide?

• The amino acid sequence

• DNA (genes) tell the cell what order to put the amino acids in

• The primary structure helps to dictate the secondary and tertiary structure

• Chemical nature of backbone and R-groups

Secondary Structure of a Polypeptide?

• Coils and folds

• Result of hydrogen bonding within the backbone of the chain

}C=O and H-N

• Alpha helix

• Beta pleated sheet

Tertiary Structure of a Polypeptide?

• Overall shape that results from interactions between R groups

}Hydrogen bonds

}Disulfide bridges

}Ionic bonds

}Hydrophobic interactions

Quaternary Structure of a Polypeptide?

• The interaction of two or more polypeptide chains

• Not all proteins have a 4^th level of structure

Why doe shape matter in a protein?

• Functions of proteins depend on recognition and binding to other molecules

• Antibodies bind to antigens on viruses/bacteria and mark them for destruction

• Morphine, heroin, and other opiates mimic shape of naturally occurring endorphins

Endorphins are neuropeptides.

• Fit into protein receptors and trigger a cellular, then physiological response

Why correct protein folding is important?

Correct protein folding is vital because a protein's specific three-dimensional shape determines its biological function. Without the proper shape, a protein cannot bind to its target molecules, catalyze chemical reactions, or support cellular life. Misfolded proteins lose their normal activity and can form harmful clumps linked to serious illnesses.

Central dogma?

The central dogma of molecular biology, proposed by Francis Crick in 1958, is the foundational concept explaining the unidirectional flow of genetic information within a biological system: from DNA to RNA to protein. It dictates that genetic instructions are stored, copied, and translated to build the functional molecules of life

Denaturation?

• The loss of the native shape of a protein

• Structure à function

} loss of shape means loss of function

• Caused by any environmental factor that disrupts the interactions

}Change in pH (why buffers are important)

}Change in salt concentration

}Increase in temperature (egg white)

Be able to example WHY these things cause denaturation using what you know about the bonds responsible for each level or protein interaction.

}Change in pH (why buffers are important)

}Change in salt concentration

}Increase in temperature (egg white)

🧪 Change in pH

• Bonds disrupted: Ionic bonds (salt bridges) and hydrogen bonds.

• Why it happens: Altering H+ ion concentration changes the charges on amino acid side chains (R-groups).

• The result: Repulsions occur or attractive ionic pairs are destroyed, breaking the tertiary structure.

🧂 Change in Salt Concentration

• Bonds disrupted: Ionic bonds and hydrogen bonds.

• Why it happens: Excess salt ions shield and compete with the charged R-groups of the protein.

• The result: Normal attractive interactions between amino acids are blocked by the salt ions, causing the protein to unfold.

🔥 Increase in Temperature

• Bonds disrupted: Hydrogen bonds and hydrophobic interactions.

• Why it happens: Added heat increases the kinetic energy and molecular vibrations of the protein atoms.

• The result: The rapid movement overcomes and breaks weak heat-sensitive bonds, though covalent peptide bonds remain intact.

Why do you think there is such a big demand for peptides?

What evidence should manufacturers of these drugs have to provide for the drugs to be approved?

Why Demand is High

• Targeted action: They fit exact cell receptor keys.

• Fewer side effects: They mimic natural body signals.

• New uses: They treat weight loss and chronic diseases well.

• Better tech: Labs make them faster and cheaper now.

Rules for Drug Approval

• Lab data: Show how the peptide works in cells and test animals.

• Safety tests: Prove the drug does not cause toxic harm in early human trials.

• Phase trials: Test large groups of people to prove the drug heals or helps.

• Quality control: Show clean, exact methods used to make the drug batch by batch.