General Biology 1 Quiz 1

Oxygen has __ protons?

8

Hydrogen has __ protons?

1

Nitrogen has __ protons?

7

Carbon has __ protons?

6

What is an isotope?

Atoms of the same element that have the same number of protons but different numbers of neutrons

Difference between an atom and an element?

An atom is the smallest chemical unit of an element that cannot be broken down further while an element is a larger more pure substance made up of the same atom

What are the components of an atom?

Proton, Electron shell, Electron, Neutron, Atomic Nucleus

Why is the number of protons in an element relevant?

The number of protons determines the identity of the element

How do electrons store and release energy?

electrons absorb energy by moving to higher energy levels, increasing their speed of movement and release energy by moving into lower energy levels due to the strong attraction to the nucleus and reduced speed of movement of the electron

Why are electrons important in cells?

Electron transfers allow cells to carry out chemical reactions and transfer energy, including the production of ATP.

How does the number of neutrons affect atomic stability

the increase in neutrons increases the mass of the atom, increasing the likelihood of the atomic nucleus breaking apart and releasing energy and particles in the form of radiation

How are isotopes used in dating fossils

by measuring the amount of carbon14 remaining in the tissue of the animal compared to the atmosphere after it continuously decays at a known rate

How are isotopes used in medicine

Isotopes can reveal areas of high chemical activity, detecting cancer in the body through PET scans due to radiation being released by isotopes of atoms in cells with high metabolic activity

How are isotopes used in forensics

Radioactive isotopes can help investigators determine where a person lived during different stages of their life because the isotopes found in local drinking water become incorporated into tissues such as hair, nails, bones, and enamel.

How is an atom converted into an ion?

One of two atoms with significantly different electronegativities transfers an electron, making one atom negatively charged and the other positively charged.

Whats the difference between a salt and a molecule?

A salt results from the ionic bonding between positively and negatively charged ions, whereas a molecule is formed the sharing of one or more pairs of electrons.

Why are ionic bonds important in biology?

Ionic bonds maintain the shape of biological molecules

What is a chemical bond?

A bond that joins atoms together to form molecules or salts

How do covalent bonds form?

When atoms share one or more pairs of electrons to form a molecule

Why are covalent bonds important in biology?

Covalent bonds are the most common and strongest bonds. They stabilize the structure of all biological molecules

Difference between non polar and polar covalent bonds?

Polar covalent bonds involve an unequal sharing of electrons between two atoms, whereas non-polar covalent bonds involve an equal sharing of electrons

What is electronegativity?

The attraction an atom has for electrons

What determines electronegativity?

The number of protons inside the atomic nucleus

How does electronegativity make a covalent bond polar or non polar?

The difference in electronegativity of the atoms creates a charge seperation and an imbalance of electrons in one atom, making it polar. When atoms have similar electronegativities they are considered nonpolar.

Difference between an atom and an ion?

Ion is a charged particle and does not have the same number of protons as electrons. An atom has the same number of protons as electrons and is neutral.

How do hydrogen bonds form?

Through the partial charges between hydrogen atoms and polar molecules

Why are hydrogen bonds weaker than ionic bonds?

Hydrogen bonds are bonds between partial charges while ionic bonds are bonds between complete charges

Why are hydrogen bonds important in biology?

Hydrogen bonds maintain the structure of biological molecules such as DNA. DNA containing weak hydrogen bonds allows for easy unzipping of the DNA strand and copy of genetic material.

Difference between van der waal interactions and hydrogen bonds?

Hydrogen bonds are stronger and are between a hydrogen atom and another electronegative atom, while van der Waals interactions are weaker, universal attractions caused by temporary random shifts in electron density.

Carbohydrates

sugars that are composed of carbon hydrogen and oxygen atoms

Glucose + Glucose?

maltose

Galactose + Glucose?

Lactose

Glucose + Fructose?

Sucrose

Glucose + Starch ?

Glycogen

Lipid

Non polar hydrophobic molecule

Fat

Type of lipid made of glycerol and fatty acids

Unsaturated fat

A fat whose carbon chain contains one or more double covalent bonds between carbon atoms, removing hydrogen atoms, creating bends in the chain, preventing tight packing and keeping the fat liquid at room temperature

Saturated

A fat whose carbon chain contains only single covalent bonds, making every carbon atom fully bonded to hydrogen and having the maximum amount of hydrogen atoms, creating a straight hydrocarbon chain that packs tightly, and making the fat solid at room temperature.

Phospholipid

special lipid made of a hydrophilic phosphate head and two hydrophobic tails that line up in a double layer to form the main barrier of cell membranes.

steroid

A lipid with a carbon skeleton containing four carbon rings that do not have fatty acid tails. They act as chemical messengers and help stabilize cell membranes as cholesterol.

Fatty acid

long chain of carbon atoms bonded to hydrogen atoms with an acid group at one end that serve as the building blocks of fats

cholesterol

type of steroid lipid with a four-ring carbon structure serving as a vital component to stabilize cell membranes by inserting itself inside to regulate how tightly packed it is

Proteins

macronutrient made of long chains of amino acids, essential for building and repairing tissues, driving chemical reactions as enzymes, and supporting immune defense

peptide

A short chain of amino acids linked together by peptide bonds that are smaller, simpler versions of proteins that act as chemical messengers in the body

Why are lipids non polar?

There is no charge separation in the hydrocarbon chain since carbon and hydrogen have similar EN

Function of fats?

Provide twice as much energy as carbohydrates due to high energy electrons in bonds, keeps body warm by preventing heat loss through the skin, and provides cushion to vital organs

Function of phospholipids?

Phospholipids have a water-loving head and a water-fearing tail, regulating what enters and leaves the cells