Overview of Proteins, Nucleic Acids, and Cell Structure

Proteins

Polymer

Monomer

Amino Acid

Functions of Proteins

Structural support, storage, transport, cellular communications, movement, defense against foreign substances

Peptide bonds

How you make a protein

Functional proteins

Consist of one or more polypeptides twisted or folded into unique shapes

Enzymatic proteins

Selective acceleration of chemical reactions

Defensive proteins

Protection against disease

Storage proteins

Storage of amino acids

Transport proteins

Transport of substances

Hormonal proteins

Coordination of an organism's activities

Receptor proteins

Response of the cell to chemical stimuli

Contractile/ Motor proteins

Movement

Structural proteins

Support

Primary Structure

Unique sequence of amino acids (determined by DNA)

Secondary Structure

Due to H-bonds between side chains

Tertiary Structure

When curls and flat sheets start folding on top of each other and in between

Quaternary Structure

Results when a protein consists of multiple polypeptide chains

Renaturation

Refolding of protein structure after being heated and unfolded

Polymer

A long molecule consisting of many similar building blocks

Polymer Synthesis

Dehydration reaction occurs when two monomers bond together through the loss of a water molecule

Mutation

Any change in DNA

Nucleic Acids

Two types of nucleic acids: Deoxyribonucleic acid (DNA) and Ribonucleic acid (RNA)

Nucleotide

Nucleoside + phosphate group

Nucleoside

Nitrogenous base + sugar

DNA

One strand 5'-3', the other 3'-5', and bond to their pair (Ex, A-T, G-C)

Length of DNA in cells

7 feet of DNA in every cell

Histones

Proteins that help package DNA in the nucleus

ATP

Derived from RNA nucleotide, has two more phosphates

Energy metabolism

Special function of ATP

Lipids

Storage of energy (Not polymers)

Categories of Lipids

3 Categories: Triglycerides, Phospholipids, Sterols/ Steroids

Triglyceride

Glycerol backbone + 3 fatty acid chains

Saturated Fatty Acids

Maximum number of hydrogen atoms possible/ no double bonds

Unsaturated Fatty Acids

Have one or more double bonds

Liquid state of fats

The more double bonds, the more likely they are to be liquid at room temperature (Ex, oils)

Fats

Long, saturated (no double bonds)

Oils

Short, unsaturated (contains a double bond)

Fatty Acid Carbon Count

All fatty acids that organisms use will have an even number of carbons

Phospholipids

Amphipathic; Two fatty acids (diglyceride) and a phosphate group are attached to glycerol

Phospholipid Structure

Head → Polar, Legs → Nonpolar

Phospholipid Bilayer

When added to water, they self-assemble into a bilayer

Steroids

Lipids that have a carbon skeleton consisting of four fused rings

Cholesterol

An important steroid, a component in animal cell membranes

Carbohydrates

Polymers (polymer ones made from glucose only)

Monosaccharides

Hexoses (6 carbons) → Glucose, galactose, fructose

Disaccharides

Maltose, sucrose, lactose (glucose + ___)

Polysaccharide

Starch, fiber, glycogen (animals)

Beta and Alpha Bonds

Plants will alternate beta and alpha bonds up and down

Dietary Fiber

Soluble → Binds water and allows for the stomach to empty more slowly.

Eukaryotic Cells

Contains nucleus; includes protists, fungi, animals, and plants

Prokaryotic Cells

No nucleus; smaller/ simpler; includes bacteria and archaea

Nucleus

Contains most of the cell's genes and is usually the most conspicuous organelle

Plasma Membrane

Basic building block: phospholipid bilayer

Ribosomes

Particles made of ribosomal RNA and protein; carry out protein synthesis in two locations: the Cytosol and outside the endoplasmic reticulum

Mitochondria

Sites of cellular respiration, a metabolic process that uses oxygen to generate ATP

Chloroplasts

Site of photosynthesis; Thylakoid contains chlorophyll and a matrix inside