Unit 2 Flashcards
What are the functions of carbohydrates?
Energy storage and cell surface molecules
Are carbohydrates primarily used in plant or animal cell storage?
Plant cells
What are amyloplasts?
Non-pigmented organelles found in some plant cells, used for storage
What is glycogen in animal cells?
A complex carbohydrate used for storage in animal cells
What is cellulose in plant cells?
A structural carbohydrate
What are both monosaccharides and disaccharides?
Simple sugars
What are examples of monosaccharides?
Fructose, glucose, and galactose
What are examples of disaccharides?
Sucrose, lactose, and maltose
What is the structure of monosaccharides?
Rings
What are some common carbs?
Simple sugars, dietary fibers, and starch
What is dietary fiber?
Cellulose, also glucose
What is starch?
Glucose
Which of the following contribute simple sugars in the form of a disaccharide? (corn syrup, modified food starch, sugar, hydrogenated soybean oil, and non-fat milk)
Sugar, non-fat milk, and corn syrup
Which class of carbohydrates does cellulose belong to?
Polysaccharides
Which class of carbohydrates does glucose belong to?
Monosaccharides
Which class of carbohydrates does sucrose belong to?
Disaccharides
How can you identify simple sugars?
-ose as an ending, or sweet
How can you identify dietary fibers (cellulose)?
Rule - structural component of plant cells
How can you identify starches?
Rule - long-term energy storage for plants (roots, seeds), digested by hydrolysis in germinating seeds to provide glucose energy
What carbohydrates are able to be absorbed into the bloodstream?
Monosaccharides only
Where are hydrolysis enzymes located?
In the mouth and small intestine
Which enzyme digests starch (amylose)?
Amylase
What is starch (amylose made up of?
Many glucoses
What is sucrose made up of?
Glucose and fructose
What is lactose made up of?
Glucose and galactose
Why is cellulose difficult to digest?
Glucose is linked differently in starch and cellulose
Why is cellulosen(fiber) calorie-free?
We do not make digestive enzymes that can recognize the bonds
Why do we eat fiber then?
We need 25-30 grams a day to feed our beneficial gut microbes
What is glycoalyx?
Carbohydrate-rich layer forming the outer coat of cells, which protects microvilli in the intestine
Which of the following is naturally indigestible because it is composed of mostly cellulose?
Wheat bran
What is the function of lipids?
Store energy, and act as membranes and steroid hormones
Half of the calories in a serving of Totino’s Party Pizza (1/2 pie) come from fats. Identify which of the following ingredients contributed fat to the pizza. (enriched flour, mozzarella cheese substitute, non-fat milk)
Mozzarella cheese substitute
What are the two major lipids found in food?
Triglycerides and cholesterol
What are triglycerides found in and their function?
Fats and oils, used for stored energy
What is the function of cholesterol?
Component of animal cell membranes, aids in flexibility, and starting material for steroid hormone synthesis
What is the third major lipid not found in food?
Phospholipids
What is the function of phospholipids?
The major component of all plasma (cell) membranes
What is the structure of triglycerides?
One glycerol with 3 fatty acids
What are some characteristics of fats?
Solid at room temperature, enriched in animal sources, and coconut oil, and palm oil, and saturated in hydrogens
What are some characteristics of oils?
Liquid at room temperature, enriched in plant sources like seeds, and unsaturated in hydrogens
Which of the following would contribute mostly saturated fat to a food? (butter, enriched flour, soybean oil, sugar)
Butter
What is the structure of phospholipids?
Glycerol with 2 fatty acids and phosphate group
What is the most concentrated energy source?
Fats/oils
What is the recommended percentage of calories to be gotten from fats and oils?
25-35%
What is the structure of steroids?
Four fused rings of carbon
What are some steroid hormones?
Estrogen and testosterone
Which of the following ingredients contributes cholesterol to foods? (soybean oil, sugar, chicken, corn syrup, starch)
Chicken
How are trans fats made?
By adding hydrogen to liquid vegetable oils to make them more solid
Why are trans fats mostly banned?
They raise your bad (LDL) cholesterol levels and lower your good (HDL) cholesterol levels, increasing your risk of developing heart disease, type 2 diabetes, and stroke
Why were trans fats used?
Cheap to produce and last a long time
What are some trans fats examples?
Buttered popcorn, coffee creamer, and pizza dough
How is cholesterol packaged in the blood?
Within lipoproteins, with a triglyceride/cholesterol core with a surface coat of phospholipids, cholesterol and protein
What is good cholesterol?
High-density lipoprotein cholesterol, carrying cholesterol to liver for elimination
What is bad cholesterol?
Low-density lipoprotein cholesterol, carrying cholesterol to cells
What is the key difference between phospholipids and fats?
Phospholipids have two fatty acids, and fats have three
What is the function of proteins?
Structure (in animals), enzymes, protection, hormones, signaling, etc.
What is the structure of proteins?
Strings of amino acids, each containing at least one N atom
How many different amino acids are there?
20
How many essential amino acids can our body not manufacture?
8
How can you identify foods with protein?
All living organisms, but all 8 essential amino acids are present in animal protein (meat, eggs, milk)
What is the function of DNA?
Carry the cell’s genetic blueprint and carry instructions for its functioning
What is DNA’s composition?
Monomers called nucleotides
What are DNA’s base pairs?
A-T and G-C
What are RNA’s base pairs?
A-U and G-C
What is alcohol metabolism?
The path alcohol takes from being ingested to being eliminated from the body?
What is a simplified enzyme-catalyzed reaction?
Substrates) + Enzymes -> Enzymes and Substrates -> Enzymes and Products
What do substrates do?
Act as reactants
What do enzymes do?
Mediate specific steps
What are products?
What you get at the end
What cells make the enzyme?
Liver and intestinal cells
What is the enzyme-catalyzed reaction for alcohol disappearance?
Alcohol (ethanol) -> Alchohol dehydrogenase -> Acetaldehyde
How is alcohol broken down?
By different enzymes
Describe a metabolic pathway?
When enzymes act ‘in series’ to break down alcohol in a stepwise fashion
What happens to acetaldehyde?
Aldehyde dehydrogenase breaks it down into acetate
What is acetate used for?
Subsequent reactions use it in cellular respiration to make CO2 and H2O which are eliminated
What is Antabuse?
A drug prescribed to alcoholics that blocks acetaldehyde dehydrogenase enzyme function, causing acetaldehyde to stay in the blood, keeping adverse reactions around
What can be said about individuals with alcohol flushing and the risk of developing alcoholism?
Less likely to develop alcoholism because you experience worse effects more quickly
Why are flushing reactions caused?
Because ethanol is being converted too quickly into acetaldehyde (alcohol dehydrogenase works too fast)
What does ADH2 code for?
Part of alcohol dehydrogenase
What does ADH3 code for?
Another part of alcohol dehydrogenase
What does ALDH2 code for?
Aldehyde dehydrogenase enzyme
What enzyme converts alcohol to acetaldehyde?
Alcohol dehydrogenase
What enzyme converts acetaldehyde to acetate?
Aldehyde dehydrogenase
What are alleles?
Two different versions of the same gene
What are ALDH21 and ALDH22?
Two different alleles of the same gene
What is a genotype?
The two alleles each person has
What is a phenotype?
The physical traits one’s genes produce
What is the pattern of ALDH2 genotypes in alcoholics versus non-alcoholics, and what does this indicate about version *1 and *2 of ALDH2?
Alcoholics have higher frequencies of ALDH version 1, and a lower frequency of ALDH version 2, indicating that ALDH version 1 may indicate a predisposition to alcoholism
What is the pattern of ADH2 genotypes in alcoholics versus non-alcoholics?
Non-alcoholics have a lower frequency of version 1 of ADH2 than alcoholics
What is the pattern of ADH3 genotypes in alcoholics versus non-alcoholics?
Non-alcoholics have a higher frequency of version 1 of ADH3 than alcoholics, and alcoholics have a higher frequency of version 2 of ADH3 than non-alcoholics
Which genes might lead to a predisposition to develop alcoholism?
ADH2 version 1, ADH3 version 2, and ALDH2 version 1
Describe characteristics associated with ADH2 version 1?
Alcoholics, slow reaction, no glow
Describe characteristics associated with ADH2 version 2?
Non-alcoholics, fast reaction, glow
Describe characteristics associated with ADH3 version 1?
Non-alcoholics, fast reaction, glow
Describe characteristics associated with ADH3 version 2?
Alcoholics, slow reaction, no glow
Describe characteristics associated with ALDH2 version 1?
Alcoholics, fast reaction, no glow
Describe characteristics associated with ALDH2 version 2?
Non-alcoholics, slow reaction, glow
What does it mean to have two versions (*1 and *2) for the ADH2 gene?
It means that you have a change in the sequence of nucleotides in the DNA that results in a change in the sequence in mRNA of that gene that is translated into a few differences in the amino acids that are found in the protein
How is the ADH21 protein produced different from the ADH22 protein?
One amino acid has been changed
Promoter definition?
Region on the DNA where RNA polymerase binds, calls attention of RNA polymerase to specific gene that needs transcribing/recruits the enzyme that produces RNA to the start of a gene
RNA polymerase function?
Attaches to the promoter and begins to unwind DNA and build a complementary strand (elongation), catalyzes the formation of RNA from a DNA template
mRNA definition?
The sequence of RNA complementary to DNA that comes out of the transcription process, carries the directions for protein synthesis to the cytoplasm, provides the code that specifies a particular amino acids
tRNA function?
Matches amino acids with the correct codon in the mRNA
Ribosome function?
Brings together and attaches amino acids to form particular proteins
What are polypeptides?
The final finished product of translation
What is transcription?
RNA polymerase enzyme uses one strand of DNA as a template to produce a copy of RNA
What is translation?
Ribosomes used tRNA to “read” messenger RNA and assemble the amino acids they carry into a new protein