BIOLOGY 12 QUEST (copy)

What is homeostasis?

The ability of the body to keep its internal environment stable and uses the hypothalamus

How does homeostasis regulate the body?

Regulates the body through feedback mechanisms that detects changes in the body and make adjustments to bring it back to normal

whats the % of water that makes our mass?

60%

Whats the most important characteristic of water?

The most important characteristic of water is that its a polar molecule

What does it mean when water is polar

Water polar because electrons are shared unequally between oxygen and hydrogen atoms, since oxygen atoms attract electrons more the oxygen-side becomes slightly negative ad the hydrogen-side becomes slightly positive

What bond is formed in water molecules and what’s the cause to this?

Hydrogen bonds are formed and this is because opposites attract to each other

What are the 7 characteristics of water?

1. cohesion

2. adhesion

3. solid is less dense than liquid water

4. good lubricant

5. high specific heat capacity

6. excellent solvent

7. very common

what does it mean when water has cohesion?

molecules stick to themselves creating surface tension

→ exp: Insects walking on water

what does it mean when water has adhesion?

Molecules stick to other polar molecules allowing it to spread

What happens when cohesion and adhesion work together?

Capillary action happens. Which happens when water molecules move through tiny spaces by adhering to polar surfaces and by cohering to each other

→ Example: Up plant stems and roots

What happens when solid ice is less than liquid water?

It floats, which is why bodies of water don’t freeze from bottom up and instead have a layer of insulating ice on the top

what does it mean when water is a good lubricant?

It can cohere under pressure in joints

what happens when water has a high specific heat capacity?

it requires a lot of energy to change its temperature

→ take more energy to boil compared to oil because of hydrogen bonds between water molecules being broken)

→ water warms/cools slowly allowing for a stable body temperature

What does it mean when water is a excellent solvent?

Polar molecules like water attracts ± ions and polar molecules

What does it mean when a substance is neutral and what’s the pH level?

There’s an equal amount of hydroxide and hydrogen, it’s pH level should be 7

What does it mean when a substance is acid/acidic and what’s the pH level?

There’s more hydrogen in the solution, it’s pH level should be less than 7

What does it mean when a substance is a base/basic and what’s the pH level?

There’s more hydroxide in the solution, it’s pH level should be greater than 7

What does a pH scale show?

It measures how acidic or basic a solution is

How can you neutraliz acids?

Bases are used to neutralize acids by removing excess hydrogen ions by hydroxide, forming water.

→ example: acid + base→ water + salt; HCI + NaOH→ water + NaCI

What are buffers?

Buffers absorb excess acids or bases to keep pH stable. They help maintain homeostasis by preventing sudden pH changes, allowing cells and chemical reactions to function properly.

Whats bloods pH?

7.35-7.45

What’s stomach enzymes pH?

2-4

What is organic compounds?

• Contains carbon atoms

• Has covalent bonding

• Exp: Glucose and CO2

What is inorganic compounds?

• Does not contain carbon atoms

• Has Ionic bonding

• Small # of atoms

• Exp: Water

What are the six elements living things are made of?

• C

• H

• O

• P

• N

• S

What does C. Hopkins Cafe + Mg stand for?

Carbon, Hydrogen, Oxygen, Phosphate, Potassium, Iodine, Nitrogen, Sulfur, Calcium, Iron, and Magnesium

What are monomers?

Small building blocks

What are polymers?

Large molecules made of smaller monomers joined together

What are most compounds in the body formed by?

Subunits/monomers joining into chains/polymers

What does amino acids make?

Proteins

What do sugars make?

Carbohydrates

What do nucleotides make?

Nucleic acids

What do FA/Glycerol make?

Lipids/Fats

What are carbohydrates?

They are the main source of energy and obtained from plants. It can exist singly or as a polymer with 2 or more monomers, are polar molecules making them hydrophilic

what are carbohydrates made of?

Carbohydrates are made of: Carbon, Hydrogen, and Oxygen in a 1:2:1 ratio.

How is carbohydrates made?

Plants make carbohydrates through photosynthesis: Carbon dioxide + Water → glucose + Oxygen gas.

Why are things hydrophilic and hydrophobic?

Polarity determines whether something is hydrophilic/hydrophobic because polar molecules have an uneven distribution creating ± areas that attract water making them hydrophilic. Non-polar molecules have an even distribution and don’t interact well with water, making them hydrophobic

What are monosaccarides?

Are sugars formed of single monomers, most important have ring structures

What does a glucose structure look like?

What does a fructose structure look like?

Which is more sweeter fructose or glucose?

Fructose is more sweeter

What are isomers?

Same molecular formula but different shape/arrangement

What are disaccharides?

Are two monosaccharides bonded together

sucrose=______+______

glucose + fructose

Maltose=_______+________

Glucose + Glucose

Lactose= ______+_____

Glucose + Galactose

What’s dehydration synthesis?

A chemical rxn where a polymere being formed as water molecule is removed

What’s hydrolysis synthesis?

Is the opposite of dehydration synthesis, its a chemical rxn where water is added to break polymers

What are polysacharides? What are the 3 major examples

Many monosaccharide units

3 major examples:

1. Starch

2. Glycogen

3. Cellulose

What is starch?

Produced by plants and bonded glucose

What is glycogen? what does the structure look like?

Produced by animal cells to store glucose in liver and muscles as reserve energy when blood sugar drops. More branched then starch but glucose molecules are right side up

What is Cellulose?

Is a fiber found in plant cell walls. Made of glucose chains with every 2nd glucose upside down. Humans can’t break the bonds so its undigested. Hydrogen bonds cause cellulose to form layers/sheets

What are 4 examples of lipids?

fats, oils, waxes, and steroid hormones

What are lipids? what are the main functions?

They’re non-polar and have 6 major functions.

1. store energy after glycogen is used up

2. a major part of cell membranes

3. acts as carriers for fat-soluble compounds including vitamins

4. provide the base for hormone synthesis

5. body insulation

6. waterproofing

What are the 4 classes of molecules?

1. triglycerides

2. waxes

3. steroids

4. phospholipids

What are triglycerides?

Also known as neutral fats can be solid or liquid at room temperature. If solid it’s a fat and if it’s a liquid it’s an oil. It’s stored in the human body in and around the muscles, brain, and under skin. It can be saturated and unsaturated fats

Whats triglycerides used for?

It used for body insulation and energy storage

Whats triglycerides composed of?

It’s composed of glycerol and 3 FA (Acid is Carboxylic acid).

What happens when we digest fat and polysacharides?

When we digest it, we use a process called hydrolysis

What does saturated fats mean?

Produced by animals and have carbon chains full of hydrogen

What does unsaturated fats mean?

Produced both by plants and animals. It has carbon chains with room for hydrogens

What are waxes?

Made when long-chain FA join with single alcohols or carbon rings and is used for water proofing

→ Exp: Leaves

What are steroids?

Has four interconnected carbon rings, 3 rings 6-C and 1 is 5-C.

What are examples of steroids?

Cholesterol, bile salts, reproductive hormones (testosterone), and adrenaline

What is cholesterol?

Raw material for making hormones and is added to cell membranes to change their fluidity

what are bile salts used for?

To help digest fats

What are phospholipids?

Are the main molecule of all cell membranes. has glycerol, 2 fatty acid chains, a phosphate, and an organic compound. The phosphate head is polar and hydrophilic, while the fatty acid tails are non-polar and hydrophobic. Having both makes it amphipathic.

What happens when phospholipids interact with water? give an exp using soap

The head dissolve and the tails group together away from the water

→ Exp: soap: Its hydrophilic heads face water while hydrophobic tails trap oil, forming micelles.

How to draw Phopholipid

Glycerol structure

Phospholipid structure (js need to recognize)

What are the major functions of nucleic acids?

Nucleic acids transmit inherited info such as genes, from generation to the next. They determine which proteins a cell makes by providing instructions and allow energy to flow in cells (ATP)

What are the two classes of nucleic acids? Explain what each one is

1. DNA (Deoxyribonucleic acid): Transmits genetic info to the next generation, has a double strand and forms a coil shape called a double helix

2. RNA (Ribonucleic acid): Used for protein synthesis and has a single strand

What are nucleic acids made of?

nulecotides

What are the 3 parts of a nuleotide

1. 5- carbon ribose

2. phosphate group

3. nitrogenous base ( there are 4 nitrogenous bases: Adenine, guanine, cytosine, and thymine)

Which nitrogenous bases have two rings?

Purines have 2 rings: Adenine and guanine

Which nitrogenous bases have 1 ring?

Pyrimidines have 1 ring: Cystosine and thymine

How do nucleotides form long polymers?

they link together through dehydration synthesis

What does RNA & DNA have?

both have phosphate-sugar backbone

What holds the two DNA strands tgt?

Hydrogen bonds that are formed between certain pairs of complementary bases

What is ATP (Adenosine triphosphate)

A special nucleotide that is the energy currency of the cell

Why do ATP’s phosphate bonds require a lot of energy and what happens if it breaks?

ATP’s phosphate groups store a lot of usable energy. When the bond of the last phosphate is broken, ATP becomes ADP and releases energy that cells use for metabolic reactions.

How are ATP bonds recharged?

When the body digests sugar

How much ATP can one glucose molecule recharge

1 glucose molecule = 38 ATP molecule

What are proteins made of?

Chains of amino acids (monomers) joined by dehydration synthesis

How many amino acids are there? give 2 examples

20 common kinds

→ Exp: Glycine and valine

Generalized structure of an amino acid (need to know how to draw)

how are dipeptides formed? what does it create?

From dehydration synthesis and creates peptide bonds

Peptide bonds are the C-N bond formed between amino acids

How does a polypeptide chain grow?

when more amino acids are added to the end

What are the 4 levels of protein organization?

1. primary

2. secondary

3. tertiary

4. quaternary

What is the primary structure?

sequence of amino acids in a polypeptide chain, used to study evolutionary relationships

What is secondary structure?

When H-bonds between atoms in the polypeptide backbone causing the chain to form into a 3D coil/kink, bonds are between O-H and N-H

What are the two types of secondary structures?

1. Alpha helix: A spiral coil with 3.6 amino acids per turn. Hydrogen bonds hold the coil together. Gives elasticity and is common in hair, nails, and skin.

2. Beta-pleated sheet: Hydrogen bonds form between nearby strands, creating a folded sheet. It is flexible and can occur within one protein chain.

what is tertiary sturcture?

is the overall 3D shape of a polypeptide. It is formed by interactions between the R-groups, such as hydrogen bonds, ionic attractions, hydrophobic interactions, and disulfide (S-S) bonds between cysteine amino acids.

what is quaternary structure?

Is the arrangement of 2 or more chains that interact as protein subunits

→ Exp: hemoglobin has 4 chains

What determines protein functions?

The shape of proteins

What is protein domain and what happens when it is heated?

A domain is a compact, globular region of a protein. When a protein is heated, its domain can unfold (Denature), causing it to lose its function. If this change is permanent, its called coagulation

What are the 5 major functions of protein

1. structural components of cells and tissues

→ Exp: Keratin (nails and hair), Collagen (skin), and myosin (muscles)

2. Helps capture and release oxygen

→ Exp: Hemoglobin

3. Uses enzymes to catalyze (speed up) body’s rxn

4. provides energy when needed

5. Acts as antibodies in immune system

Steroid Structure

3 hexagons and 1 pentagon