Biomolecules and Cell Physiology

Unsaturated fatty acids have _____ double bonds in their long hydrocarbon chains.

1 or more

There are two types of nucleic acids:

1. Deoxyribonucleic acid (DNA) 2. Ribonucleic acid (RNA)

All cells have some common structures and functions • Human cells have three basic parts:

1. Plasma membrane = Flexible outer boundary 2. Cytoplasm = intracellular fluid containing organelles 3. Nucleus = control center that contains DNA

cell theory

1. The cell is the smallest structural and functional living unit 2. Organismal functions depend on individual and collective cell functions 3. Biochemical activities of cells are dictated by their specific subcellular structures 4. Continuity of life has a cellular basis

Amino acids contain

2 functional groups: an amino group (NH2) and a carboxyl group (COOH)

Collagen requires ____ chains in a superhelix

3

Proteins are generally classified according to their

3D shapes.

Proteins have _ levels of structure

4

Humans have ____ chromosomes (23 pairs), each made up of many genes

46

The N-containing base is one of

5 types

• Proteins account for _______ of the dry weight of the human body

50%

Enzymes are very specific;

; each enzyme catalyzes a certain reaction or type of reaction only.

nuclear pores

= allow necessary transport between the nucleus and the cytoplasm

nuclear envelope

= double- layered membrane which separates the nucleus from the rest of the cell

Endomembrane system =

= set of 3 organelles that work together to perform various cellular jobs -Producing -Packaging -Exporting

Denaturation

= the process of altering the shape of a protein without breaking the amide bonds that form the primary structure. High temp, acid, base, and agitation can disrupt the shape

Hydrophobic ? hydrophillic

>

The names of most enzymes end with the suffix

"-ase" like peptidase, lipase, and hydrolase.

Classes of Biomolecules

(4) carbohydrates, lipids, proteins, nucleic acids

Outer membrane and an inner membrane with many folds.

Mitochondria

The nucleotides of both DNA and RNA contain

a 5-membered ring monosaccharide, often called the sugar component

Heme=

a complex organic compound containing the Fe2+ ion (that binds oxygen) complexed with a large N-containing ring system

Endoplasmic Reticulum (ER)

a system of channels

• An enzyme contains an ____ that binds the substrate, forming an ____ complex

active site; enzyme-substrate

DNA contains the bases

adenine, guanine, cytosine, thymine

RNA contains the bases

adenine, guanine, cytosine, uracil

In DNA, the monosaccharide is the

aldopentose D-2-deoxyribose

In RNA the monosaccharide is the

aldopentose D-ribose

Hemoglobin and myoglobin = two globular proteins that are called _____________________ because they are composed of a protein unit and a nonprotein molecule

conjugated proteins

Golgi apparatus =

consists of a stack of flattened, slightly curved membrane- enclosed sacs that are responsible for sorting, modifying and shipping off products that come from the rough ER

Contractile proteins

control muscle movements

The 3D arrangement of localized regions of a protein arise

due to hydrogen bonding between the N—H group of one amide with the C═O group of another Two stable arrangements are the ⍺-helix and the β-pleated sheet

Hydrolyzable lipids are derived from

fatty acids

A __________ is the portion of the DNA molecule responsible for the synthesis of a single protein.

gene

• In the human body, they are used for bursts of energy needed during exercise in the form of

glucose

Monosaccharides

glucose, fructose, galactose (simple sugars)

Cytoskeleton =

group of fibrous proteins that provide structural support for cells Critical for cell motility, cell reproduction, and transportation of substances within the cell

• Intermediate filaments:

important in cell regions subject to mechanical stress (intermediate in diameter) 8-12 nm

The area between the two membranes of mitochondria =

intermembrane space

Fibrous proteins,

keratin and collagen give support and structure

Proteins are

large polymers of amino acids joined by peptide bonds that are responsible for a lot of the structure and function of all living cells, come from greek word proteose, of first importance

Fatty acids are carboxylic acids with

long carbon chains of 12 to 20 C atoms

The area enclosed by the inner membrane = the ____________, where energy production occurs.

matrix

Disaccharides are

molecules with two sugars 2 monosaccharides joined together sucrose, lactose, and maltose.

• Three groups of carbohydrates:

monosaccharides, disaccharides, polysaccharides

Phospholipids

the major component of cell membranes, contain a hydrophilic polar head and two hydrophobic nonpolar tails • When phospholipids are mixed with water, they assemble into a lipid bilayer • The polar heads orient on the outside to interact with polar water molecules • The nonpolar tails orient on the inside to avoid polar water molecules

Adenine (A) and guanine (G) are based on the structure of

purine

• Cytosine (C), uracil (U), and thymine (T) are all based on the structure of

pyrimidine

Protein hormones and enzymes

regulate metabolism

Rough ER: membrane dotted with _______________ (organelles that serve as the site of protein synthesis)

ribosomes

DNA molecules contain _____ nucleotides, while RNA molecules have only_____

several million nucleotides; a few thousand

The quaternary structure of a protein is the

shape adopted when 2 or more folded polypeptide chains (each with its own tertiary structure) come together into 1 protein complex

Transfer RNA (tRNA) brings

specific amino acids to the ribosomes for protein synthesis (the smallest type)

Examples of nonhydrolyzable lipids

steroids and fat-soluble vitamins, eicosanoids

The secondary structure of a protein is

the 3D arrangement of localized regions of a protein

The tertiary structure of a protein is

the 3D shape adopted by the entire peptide chain

RNA (ribonucleic acid) translates

the genetic information contained in DNA into proteins needed for all cellular function

DNA (deoxyribonucleic acid) stores

the genetic information of an organism and transmits that information from one generation to another.

Messenger RNA (mRNA) carries

the information from DNA (in the nucleus) to the ribosome.

Collagen

the most abundant protein in vertebrates and is found in connective tissues such as bone, cartilage, tendons, teeth, and blood vessels

• ⍺-Keratins

the proteins found in hair, hooves, nails, skin, and wool They are made of 2 mainly ⍺- helix chains coiled around each other in a superhelix or supercoil and are very insoluble in water • These coils wind around other coils making larger and stronger structures like hair

Ribosomal RNA (rRNA) provides

the site where polypeptides are assembled during protein synthesis in the ribosomes (most abundant)

Carbohydrates

the starches and sugars present in foods

• Nucleus =

typically the largest single organized cell component

Nucleic acids are

unbranched polymers composed of repeating monomers called nucleotides

Hydrophyllic

water loving

• Denaturation often makes globular proteins less ___

water soluble.

Examples of hydrolyzable lipids

waxes, triacylglycerols, phospholipids

B-pleated sheet=

when 2 or more peptide chains, called strands, line up side-by-side

Deoxy means

without oxygen

• Organelles of the endomembrane system:

• Endoplasmic reticulum • Golgi apparatus • Vesicles/lysosomes

Golgi apparatus has 2 distinct sides which

• One side receives products in vesicles • The other side then releases the products after they are repackaged into new vesicles

Superimposed on secondary structure..

⍺-helices and/or β-pleated sheets are folded up to form a compact globular molecule

_________________ = process of a cell digesting its own structures

Autophagy

The sugar-phosphate groups lie on the outside of the helix and the bases lie on the inside, sugar phosphate is known as the ___

Backbone

Polysaccharides

Carbohydrates that are made up of more than two monosaccharides starch, glycogen, and cellulose

Molecular formula of simple carbohydrates =

Cn(H2O)n

• Vitamin C helps stabilize the___ chains and when missing, poorly formed collagen fibers result

Collagen

The nonprotein unit in hemoglobin and myoglobin is called _____ =

Heme

There are important differences between DNA and RNA

In RNA, the monosaccharide is- ribose The thymine (T) base is not present in RNA; instead, the uracil (U) base is used. RNA is a single strand, and smaller than DNA

Biomolecules

Organic molecules found in biological systems

Carbohydrates are synthesized in green plants by ________________________, a process that uses energy from the sun to convert CO2 and water into glucose and oxygen

Photosynthesis

The ______________, called the side chain, determines the identity of the amino acid

R group

Carbohydrates = of chemical energy

Storehouse

Hydrophobic

Water fearing

The DNA model was initially proposed by

Watson and Crick in 1953

Lipids

are biomolecules that are insoluble in water -They are defined by a physical property, and not by the presence of a particular functional group • Lipids come in a wide variety of structures and have many different functions • They contain many nonpolar C—C and C—H bonds and few polar bonds resulting in their water insolubility; serve as chemical messengers in body

Fibrous Proteins

are composed of long linear polypeptide chains that are bundled together to form rods or sheets • Insoluble in water and serve structural roles

Microtubules: help maintain

asymmetric cell shapes and play a role in complex cell movements (thickest) 25 nm in diameter; made up of tubulin which is a type of protein and they make up two types of cellular apendages that are important for motion ; cilia as well as flagella

Mitochondria = membranous,

bean-shaped organelle that converts molecules (e.g. sugars) to adenosine triphosphate (ATP)

Lysosome = contains enzymes that

break down and digest unneeded cellular components, such as a damaged organelle

hydrolyzable lipids

can be converted into smaller molecules by hydrolysis = the process of using

Nonhydrolyzable lipids

cannot be cleaved into smaller molecules by aqueous hydrolysis

transport proteins

carry substances through the blood

Microfilaments: important to

cellular contractile systems and as mechanical stiffeners (thinner) 7 nm in diameter, actin is primary component to make this up

Saturated fatty acids have

no double bonds in their long hydrocarbon chains.

DNA is contained in the chromosomes of the

nucleus; each chromosome having a different type of DNA.

The primary structure of a protein is the

particular sequence of amino acids that is joined together by peptide bonds • It determines all properties and function of a protein

a-helix =

peptide chain twists into a spiral

Smooth ER = synthesizes

phospholipids and steroid hormones

DNA consists of two

polynucleotide strands that wind into a right-handed double helix. The two strands run in opposite directions; one runs from the 5ʹ end to the 3ʹ end and the other runs from the 3ʹ end to the 5ʹ end.

Enzymes =

proteins that serve as biological catalysts for reactions in all living organisms