Biochemistry Lecture Notes

Flashcards for Biochemistry review.

How do electrons behave around the nucleus of an atom?

Electrons orbit the nucleus in different energy levels, absorbing energy to jump to higher levels and releasing energy to fall back to lower levels.

What are biological systems designed for regarding energy?

Biological systems are designed to control the capture and release of energy to benefit the cell.

What kind of atoms become ions?

Atoms with a full valence shell, making them stable.

Why are ions important in biological systems?

Electrochemical gradients power cellular processes, and electrolytes dissolve in water to conduct electricity.

Give examples of Radioisotopes used in diagnosing diseases?

Iodine for thyroid and glucose for cancer diagnosis.

Which elements are more electronegative?

Oxygen and nitrogen.

Which elements are less electronegative?

Hydrogen and carbon.

What type of bond shares electrons equally between atoms?

A nonpolar (NP) covalent bond.

What are the pH values for acidic, basic, and neutral substances?

Acidic: below 7, Basic: above 7, Neutral: 7.

What composes a buffer system?

Weak bases/acids with their conjugate base/acid.

How does carbonic acid respond to a decrease in H+ ions in the blood?

Carbonic acid dissociates into H+ ions and bicarbonate.

What is an important intermolecular force?

Hydrogen Bonding.

What is Hydrophobic Effect?

The behavior of non-polar molecules in the presence of polar molecules

Where are hydroxyl groups found?

Carbs, proteins, nucleic acids, lipids, alcohols.

Where are carbonyl groups found?

Carbs and nucleic acids.

Where are carboxyl groups found?

Proteins and lipids.

Where are amino groups found?

Proteins and nucleic acids.

Where are sulfhydryl groups found?

Proteins.

Where are phosphate groups found?

Nucleic acids.

Give examples of monomers and their corresponding polymers.

Amino acids are monomers of proteins, monosaccharides are monomers of polysaccharides, and nucleotides are monomers of nucleic acids.

How do electrons behave around the nucleus of an atom?

Electrons orbit the nucleus in different energy levels, absorbing energy to jump to higher levels and releasing energy to fall back to lower levels.

Describe Beta glucose

The CH2OH and OH groups are on the same side.

Give examples of disaccharides

Maltose, Lactose, Sucrose

What are storage polysaccharides?

Starch and glycogen.

What are the two types of starch?

Amylose (unbranched) and amylopectin (branched).

Where is glycogen stored in animals?

Liver and muscle tissue.

What is the main component of plant cell walls?

Cellulose.

What are the monomers of nucleic acids?

Nucleotides.

What are the three parts of a nucleotide?

Sugar (ribose or deoxyribose), phosphate group, and nitrogenous base (A,T,C, or G).

What is the central dogma of molecular biology regarding nucleic acids?

DNA codes for RNA, and RNA codes for proteins.

Where can DNA be found?

Nucleus, mitochondrion, chloroplast.

Where can RNA be found?

Nucleus and cytoplasm.

What is the sugar component of DNA?

deoxyribose

What is the sugar component of RNA?

ribose

What are the nitrogenous bases in DNA?

ATCG

What are the nitrogenous bases in RNA?

AUCG

Are lipids polymers?

Not polymers.

What are the building blocks of triglycerides?

Glycerol and fatty acids.

What is the function of phospholipids?

Main component of membranes.

What is the nature of phospholipids?

Amphipathic (both polar and nonpolar regions).

Cholesterols is a type of what?

Steroids.

What are some functions of proteins?

Structural support, immunity, transport, movement.

What is the primary structure of a protein?

The sequence of amino acids in a polypeptide chain.

What are the two types of secondary structure in proteins?

Alpha helices and beta-pleated sheets.

What is the secondary structure of a protein due to?

Due to hydrogen bonding.

List the functions of protiens

Hormones, enzymes, structural support, immunity, transport, movement

What is the function of the cell membrane?

A boundary that separates the living cells and other stuff

What are the function for membrane proteins?

Transport (ATP), enzymatic activity, signal transduction, cell-cell recognition, intercellular joining, attachment to the cytoskeleton and extra-cellular matrix (ECM)

What is the role of Membrane Carbohydrates?

Cell-Cell Recognition

What is the role of Membrane Carbohydrates?

Cell-Cell Recognition

What prevents substances from easily crossing the membrane?

Too large, too polar, charged

How is water transported across the membrane?

Channel proteins called aquaporins also facilitate the passage of water.

What is Passive Transport?

is diffusion of a substance across a membrane without energy needed, from high concentrate —> low concentrate.

What are the methods of active transportation?

Primary active transport uses ATP to move molecules or ions across the membrane. Secondary active transport uses the electrochemical gradient created by primary active transport to move other molecules

What type of molecules are moved during bulk transport?

Large molecules, such as polysaccharides and proteins and viruses, enter/exist the cell through vesicles

What is exocytosis?

Transport vesicles migrate to the membrane, fuse with it, and release their contents; it allow the large molecules like polysaccharides, protiens exit the cells

Summarize Catabolic Reactions (breaking down the molecules)

Release energy to break down complex molecules into smaller subunits. Covalent bonds are broken by the addition of a water molecule

Summarize Anabolic Reaction (building molecules)?

Consumer energy to build complex molecules; Monomers covalently

Summarize Oxidation Reactions (OIL)

Less of elections from one substance

Summarize Reduction Reactions

Addition of electrons to anther substance (RIG)

What are enzymes?

Protein molecules that catalyze biochemical reactions.

What are competitive inhibitors?

Bind to active site, preventing substrate from entering ( thus ‘competing’ with substrates for active sites)

What is Allosteric Site?

Site on enzyme that is not the active site buy allow interaction with molecules to change activity

What are Characteristics of All Cells?

Have DNA, have cytoplasm,have a cell membrane, ribsomes

Summarize Bacterial-Like

Contain double membranes and circular DNA

Summarize Eukaryotic

Have membrane bound organelles

What are function of Cytoskeleton

Mechanical support, anchors organelles, helps move substances

What are the function of Lysosomes?

aid in cell renewal, Break down old cell parts into pieces

What does iodine test and result?

Black—> starch