AP BIO: Unit 1 test

Primary structure of Protein and bonds involved

a sequence of amino acids are bonded together through dehydration synthesis to create peptide bonds between two amino acids. The peptide bonds act as a partial double bond and inhibit free rotation, which affects the structural character of the coils and other shapes formed by chains of amino acids.

Secondary structure of proteins and bonds involved

amino acids are in a helix/pleated form due to the hydrogen bonds between amino acids, causing there to be more structure in the protein

Tertiary Structure and bonds involved

bends itself to become stable due to sulfide bridges and hydrogen bonds between R groups

Peripheral proteins

enzymes, motor proteins, cell-to-cell links, provide support on intracellular surface

Glycolipids

help with communication and signaling things

Glycoproteins

identify markers like blood type in cellular populations like your body, immune systems attacks when glycoproteins in your body aren't yours

Cholesterol

keeps the membrane fluid in extreme temps (like antifreeze, lets phospholipids continue to move)

Lipid bilayer

lets in only small nonpolar molecules

Integral proteins

like a ferry; they bring channels and carriers, enzymes, or receptors inside and outside of the cell

ribosomes

make proteins

osmosis

refers to the movement of one, less concentrated solvent through a semipermeable membrane to another, more concentrated solvent. The objective is an equalized solution.

Vesicles

small, membrane-enclosed sac that stores or transports materials

Cytoskeleton

structural support, anchors organelles, helps move chromosomes, organelles, and cell

Endoplasmic Reticulum

structure: cisternae function: manufactures membranes from the cell and makes proteins with the help of ribosomes

Extracellular matrix

the extracellular matrix largely determines how a tissue looks and functions

Smooth E.R.

-synthesizes lipids -metabolizes carbs -detoxes drugs by adding a hydroxyl group and making it more soluble

Why are proteins the most complex biological molecules?

Because they have many different functions based on their structure. The structure of a protein depends on the sequence of amino acids and there are 20 different amino acids, which can be assembled in any order, so there are a lot of ways a protein can be folded. This is why proteins have many functions which are categorized into 7 main functions: defense, transport, support, enzyme catalysis, motion, regulation, and storage

Explain the three major structural differences between DNA and RNA.

DNA - double helix, pentose sugar = deoxyribose, uses thymine (T) RNA - single helix, pentose sugar = ribose, replaces T (thymine) with U (uracil)

Chemically, what is the difference between a saturated fat and an unsaturated fat? How does this difference affect the properties of the molecules?

In a saturated fat, all of the carbons are bonded to two or more hydrogens. In an unsaturated fat, there is at least one double bond between carbons, meaning that one or more carbons are only bonded to 1 hydrogen. Having double bonds changes the behavior of the molecule because free rotation cannot occur about a C=C double bond as it can with a C-C single bond. This mainly affects melting point: saturated are solid, while unsaturated are liquid at room temperature.

How can you tell a biological molecule is a lipid?

Lipids are insoluble in water and have a high proportion of nonpolar carbon-hydrogen bonds. They are composed of glycerol and fatty acids.

real world example of osmosis

Example of Osmosis: Pruned Fingers If you've ever been a bath or pool too long, then you've seen your fingers and toes get pruney. Most people assume that you are "pruning" up by losing water, but this is not the case, your fingers actually become bloated. This makes it easier to understand the original idea of osmosis: moving from a less concentrated substance to a more concentrated substance. In this scenario, the water in the bathtub is less concentrated and it is trying to cause equilibrium by using osmosis to get into your body. If you don't believe this, think about what happens when an animal (or person) drowns and then soaks in the water. Their bodies become extremely bloated, as osmosis will continue to happen until equilibrium is achieved.

How are macromolecule polymers assembled from monomers? How are they broken down?

Macromolecule polymers are assembled through a process called dehydration synthesis. In this process, an -OH group is removed from one monomer and a hydrogen atom is removed from the other. This creates a covalent bond between the monomers. Macromolecule polymers are disassembled through a process called hydrolysis. During hydrolysis, a hydroxyl group is added to one monomer and a hydrogen atom is added to the other to break the covalent bond between the two.

Explain the relationship between monosaccharides, disaccharides, and polysaccharides.

Monosaccharides are simple sugars and are composed of one sugar. They are often used to form larger molecules. Disaccharides are formed by linking two monosaccharides together. Polysaccharides are longer polymers made up of three or more monosaccharides that have been joined through dehydration synthesis.

Why isn't cellulose easily broken down?

Most organisms do not have the enzyme to digest and break down cellulose.

Quaternary Structure and bonds involved

Only found in proteins with more than 2 polypeptides chains. Hydrophobic reactions that help determine structure. Much more efficient and functional.

How do organelles allow for increased complexity in cells?

Organelles carry out essential functions that are necessary for the survival of cells-harvesting energy making new proteins, getting rid of waste and so on, varied organelles allow more "jobs" to get done in the cell by smaller units rather than needed in the larger unit for each. Organelles can have have different conditions (like pH and temperature), and the function that these organelles perform are dependent upon its conditions which allows for increased complexity within cells.

passive transport

Passive Transport does not require energy in order to move things in a direction of high to low. (like osmosis)

Explain how the structure of proteins and nucleic acids allow for their biological functions.

Proteins: Because there are 20 different amino acids that can be assembled in any order, there are so many different shapes proteins can have. The shape of the protein determines its function. Example: The shape of hemoglobin enables it to move through human veins and arteries transporting oxygen and carbon dioxide. Nucleic Acids: The weak hydrogen bonds between nitrogen bases in DNA make it easy to separate strands and replicate them. The fact that DNA strands are complementary also helps for reproduction of cells. (mitosis and meiosis)

Explain why directionality and sequence are crucial for the structure and function of proteins and nucleic acids.

Sequence - In nucleic acids, the specific sequence of nucleotide bases determines the genetic information that DNA stores. For RNA, the sequence directs protein synthesis. In proteins, the sequence of amino acids ultimately determines the overall shape of the protein and therefore the function. Directionality -Nucleic acids have ends: the 5' phosphate end and the 3' hydroxyl end direct which nucleotides will be added during DNA synthesis and the direction in which the process occurs. .....

How are triglycerides, phospholipids, and steroids similar? How do they differ?

Similarities - hydrophobic, lipids, nonpolar molecules, insoluble in water Triglyceride - molecule with 3 fatty acids bonded to a glycerol backbone; main function = long term energy storage Phospholipids - molecule with 2 fatty acids and a phosphate attached to a glycerol backbone. (often with another molecule on the phosphate) important for cell membranes, (polar head + nonpolar tails = phospholipid bilayer) Steroids - composed of 4 carbon rings and a functional group, serve as hormones, are in most animal cell membranes

Why are starch and glycogen useful as energy storage molecules, while cellulose is useful for structure and support?

Starch and glycogen are useful for energy storage because their structure allows them to be easily digested by organisms. The structure of cellulose makes it good for structure and support.

FLUID MOSAIC MODEL

The fluid mosaic model describes the structure of the plasma membrane as a mosaic of components—including phospholipids, cholesterol, proteins, and carbohydrates.

Golgi Apparatus

The golgi apparatus is a series of multiple compartments where molecules are packaged for delivery to other cell components or for secretion from the cell. -glycosilation to proteins -products are added to proteins -folding of the protein PROTEINS BECOME MORE COMPLEX SO THEY CAN HAVE UNIQUE AND DIFFERENT FUNCTIONS FOR PARTICULAR THINGS

Why are particular substances able to or not able to pass through the phospholipid bi-layer of the cell membrane?

The most important property of the cell membrane is its selective permeability: some substances can pass through it freely, but others cannot. Small and nonpolar (hydrophobic) molecules can freely pass through the membrane, but charged ions and large molecules such as proteins and sugars are barred passage.

nucleus

-contains cell's genetic material -organized as DNA molecules and proteins to form chromosomes

Functions of the endomembrane system

1. synthesis of proteins and transports into membranes, organelles, or out of cells. 2. Metabolism and movement of lipids 3. Detoxification of poisons.

active transport

Active transport uses energy in order to move things in a direction from low to high. (against a concentration gradient)

Describe the roles played by carbohydrates and lipids in biological systems.

Carbohydrates are well suited for short term energy storage. In humans, glucose circulates in blood as a monosaccharide. Disaccharides serve as transport molecules in plants and provide nutrition to animals. Polysaccharides provide energy storage and structural components. Chitin in arthropods and insects provides an exoskeleton. Cellulose gives support in plant cell walls. (1. quick energy-> short term energy storage, 2. raw materials -> structural materials) Lipids provide long term energy storage. The have large numbers of C-H bonds which are strong covalent bonds and release a lot of energy when broken. They are also useful in the formation of cell membranes (phospholipids) and they act as chemical messengers in the body (hormones=cholesterol and sex hormones).

How can you tell a biological molecule is a carbohydrate?

Carbohydrates contain carbon, hydrogen, and oxygen in the molar ratio 1:2:1. The empirical formula for carbohydrates is CH2O. The monomers of carbohydrates are sugars. ends in -ose

Explain how nucleic acids and proteins function in storage and expression of biological information.

Certain proteins, such as ferritin, casein, and calmodulin, have the function of ion-binding. They bind and store various ions, including iron and calcium. Proteins are responsible for most of our appearances and bodily functions. Nucleic acids store information in the sequences of nucleotides. DNA encodes the genetic info and uses it to make proteins.

How do herbivores solve the problem of cellulose digestion?

Herbivores have evolved a mechanism to digest cellulose. These organisms have symbiotic bacteria and protists in their digestive tracts that provide the necessary enzymes for breaking the β linkages in cellulose, enabling access to energy.

How can the structure of a protein be changed/denatured?

If a protein's environment changes, the protein can change shape or unfold completely. These are changes in pH, temperature, or ionic concentration of the surrounding solution. Denatured proteins are usually biologically inactive, particularly in enzymes.

What are the chemical differences between carbohydrates and lipids?

The ratio of Carbon atoms to Hydrogen atoms in fats is twice the ratio in carbohydrates, making lipids, much more efficient for storing chemical energy lipids- nonpolar, hydrophobic, insoluble in water, no monomer, glcyerol backbone bonded to fatty acid chains carbohydrates - made up of sugars

How does the structure of the 'R' group affect the properties of a particular amino acid?

The structure of the R group determines the unique properties of amino acids. Depending on the R group, amino acids can have traits of being polar, non polar, acidic, basic, charged, or aromatic.

How does the ratio of a cell's surface area to volume place upward and downward limits on cell size?

The surface area to volume ratio limits cell size because the bigger the cell gets, the less surface area it has for its size. This is important if you are a cell that depends on diffusion through your cell wall to obtain oxygen, water, and food and get rid of carbon dioxide and waste materials. As you get bigger, your outside is unable to keep up with needs of the inside.

Why is the cell theory significant?

The theory says that new cells are formed from other existing cells, and that the cell is a fundamental unit of structure, function and organization in all living organisms. If we don't understand the cell we cannot understand the phenomenon of life, and if we cannot understand life then the biology we learn is not applicable to real life, so there would be no point to studying biology without the cell theory. The cell theory is still considered a theory because we can't prove that cells are formed from other existing cell and we can not prove where the first cell came from.

vacuoles

Vacuoles might store food or any variety of nutrients a cell might need to survive. They can even store waste products so the rest of the cell is protected from contamination.