SDSU Bio 100 Lonjaret - EXAM 4 SPRING 2025

Proteins are diverse molecules that perform a wide variety of functions. Which of the following is NOT a typical function of proteins?

Energy storage

What are the monomers of proteins?

Amino Acids

What might happen if a protein has a change in one amino acid?

The protein can no longer function properly, The amino acid chain folds incorrectly., The protein has a new shape

Enzymes are a type of ________.

protein

A protein's function is largely determined by its _____.

shape

The primary structure of a protein is like the arrangement of beads on a string. In this analogy, the beads are _____.

amino acids

A protein's α helices and β sheets form their shapes at the _____ level of protein structure.

second

What happens to the shape and function of a protein if one of the amino acids is replaced with a different type of amino acid?

It depends on the role of the amino acid that is altered. One amino acid might be replaced with no measurable effect on the protein's function; replacing another might cause a total loss of function.

Large proteins, like DNA polymerase and hemoglobin, are often composed of several polypeptides that are linked together. The _____ level of protein structure describes how the polypeptides are joined to create a larger complex.

fourth

During digestion, __________ are broken down into __________ through __________ reactions.

proteins; amino acids; hydrolysis

What is the role of the villi?

To absorb small nutrient molecules from the digestive tract

Where does most of the absorption of food nutrients take place?

In the small intestine

An essential nutrient is specifically a nutrient that your body ________.

cannot make by itself

Most of the body is _____

water (H20)

2nd most abundant molecules are _____

C-based

Four elements making up bulk of human cells

Oxygen, carbon, hydrogen, nitrogen

Oxygen make up of living cells

65%

Sulfur make up of living cells

.3%

Hydrogen make up of living cells

9.5%

Nitrogen make up of living cells

3.3%

Carbon make up of living cells

18.5%

Molecules that contain C bonded to other elements are called

organic compounds

Sets of atoms attached to the C skeleton are called

functional groups

Hydroxyl group

Amino Group

NH2

Macromolecules are

large molecules with a complex structure; most organic molecules

Polymers are

what makes up macromolecules; chains whose links are smaller molecules called monomers

4 classes of organic molecules important to life

Carbohydrates, proteins, lipids, nucleic acids

Keratin is an important component of

hair and nails

Enzymes

are always proteins and are any word ending in -ase

Proteins are polymers of

amino-acids

Monomers (amino acids) become

polymers (proteins)

Dehydration is a

H20 synthesis reaction

Polypeptide is a

chain of amino acids (twists and folds lead to a unique 3d shape)

Protein structure and function are determined by

a precise amino-acid sequence (and may not perform if the sequence is changed)

Dense irregular connective tissue

In the dermis: resists tension in any direction (isotropic)

Dense regular connective tissue

In tendons and ligaments: resists tension in same direction always like a rope (anisotropic)

Transmembrane proteins

three ion pumps, highly specific to an ion

Apamin

bee venom, smallest protein venom

anywhere you see covalent bonds (h2n=0) bonds go no where it is a ____.

Carbon bond

Complete protein meals

Require us to obtain 9 essential amino acids from our diet (other 11 come from self synthesis)

Complete proteins

have all essential Amino Acids, usually from animal products

Incomplete proteins

Often from plants

Complementary proteins

eaten together, yield all the essential amino acids

the number of protons in the nucleus of an atom, which determines the chemical properties of an element and its place in the periodic table.

atomic number

The number of protons plus neutrons in an atom, represented as an average of all naturally occurring forms of the element, is known as

atomic weight

also called micronutrients, are any chemical element required by living organisms in miniscule amounts, but cells require them to survive.

trace elements

is one of the four elements that make up 96.3% of living cells.

nitrogen

The bond in which bonded atoms share electrons is called a(n) ________.

covalent bond

____ is one of the fourteen trace elements and is a component of certain digestive enzymes and other proteins.

zinc

_____ is one of the seven elements that make up a small fraction, approximately 3.7%, of living cells.

calcium

Individual water molecules are held to one another by relatively weak ________ bonds.

hydrogen

The breaking of a large organic molecule into smaller, individual subunits involves multiple ________.

hydrolysis reactions

What is another name for the polymers of carbohydrates?

Polysaccharides

Part complete

Starch and glycogen are complex carbohydrates made by joining together long chains of __________ molecules.

glucose

In what ways are the chemical reactions of photosynthesis and cellular respiration similar?

Both release heat as a waste product.

Which of the following is a common energy currency in living cells that powers most living organisms?

ATP

What is the main purpose of cellular respiration?

make ATP

The food you eat is processed during cellular respiration to produce stored chemical energy in the form of __________, with __________ and __________ as by-products.

ATP; CO2; water

How is diabetes linked with homeostasis?

Diabetes results from the body not responding with a negative feedback to the level of glucose in the blood.

How does yeast make bread dough rise?

yeast cells produce o2

What kinds of molecules can be used as metabolic fuel to produce ATP?

Sugars, amino acids, and fatty acids

correct sequence of structures of the urinary system in the creation to the excretion of urine?

Kidneys, ureter, urinary bladder, and urethra

What is the name of the tubes that run from the kidneys to the bladder?

ureters

What is the basic structure of typical dietary fats?

A glycerol head and up to three fatty acid tails

All lipids are ________.

hydrophobic

What molecules are constituents of cell membranes?

Phospholipids, proteins, carbohydrates, and cholesterol

During which stage of cellular respiration is the majority of the ATP produced?

Electron transport chain

Which of the following cells contain a plasma membrane?

animal, plant, bacterial cells

Which would most likely pass unaided through a plasma membrane?

Something small and nonpolar, such as nitrogen gas

How does CO2 move from your blood cells into your lung cells?

Passive transport

The presence of many C-C and C-H bonds causes fats to be ..

rich in energy and insoluble in water

In fat synthesis,________and fatty acids combine to make fats plus________.

glycerol; water

In the reaction that builds a fat,________ groups react with ________ groups

hydroxyl; carboxyl

Triglycerides vary with respect to the number of ...

C atoms in the tails and double bonds in the tails

A food company hydrogenated a barrel of fat. The treatment ..

made the fat less fluid.

The most unsaturated fats have ...

the most double bonds.

What do DNA, proteins, and fats have in common?

They contain carbonyl groups.

Fatty acid chain of HO-C-CH2-CH2-etc

Carbon acid chain

Lipids are ______.

Hydrophobic

Cell membranes are 2 stacked layers of

phospholipids

Saturated fats

single bonds only

Unsaturated fats

Includes a double bond (curved bond)

Characteristics of saturated fats

Contains maximum number of H

Solid at room temperautre

All C-C single bonds

Characteristics of unsaturated fats

Less than maximum number of H

Liquid at room temperature

Some C=C bonds

Foods rich in _____ fats are part of a balanced diet

Essential

Fats containing ______ reduce risk of heart disease

w-3 fatty acids

3 fatty acids is _______

triglycerides

Roles of cholesterol

Maintain fluidity in animal cell membranes

Steroid hormone synthesis

Low-density lipoprotein

"bad cholesterol" - levels can be increased through poor diet

High density lipoprotein

"good cholesterol" Levels can be increased through exercise

Where cholesterol is found

animal derived foods such as eggs and red meat

Carbohydrates include _____ that function as fuel

macromolecules

_______ are a common source of dietary energy for animals and important building blocks of plants and are a primary source of energy

carbohydrates

________ are composed of simple sugars

carbohydrates

Individual saccharide molecules are simple sugars also known as

monosaccharides

Carbohydrates consist of one or more

monosaccharides joined together

Simple carbohydrates are

"hydrated C"

Glucose, Fructose, Galactose makeup

C6H12O6

Three fates of blood sugar

Fuel for cellular activity

Glycogen for temporary storage

Fat for long term energy storage