Nutrients/Cells Flashcards
What are Carbohydrates composed of?
C,H, O
What are the functions of carbohydrates?
- Living things use them as their main source of energy
2. Plants and some animals use carbohydrates for structural purposes.
What are the three categories of carbohydrates?
Monosaccharides,
disaccharide, and polysaccharides.
What is a monosaccharide? Give three examples.
A single sugar molecule Glucose, fructose, and galactose.
What is a disaccharide? Give the three examples.
Two ringed-sugar/two monosaccharides joined together. Lactose, sucrose, maltose.
What is a polysaccharide?
Many monosaccharides joined together/chain of rings.
What are the storage polysaccharides?
Glycogen and starch.
In animals, what storage polysaccharide is stored as the excess sugar? Where?
Glycogen, liver.
What is glycogen used for in animals?
Long term energy storage.
In plants, what storage polysaccharide is stored as the excess sugar? Where?
Starch, seeds and specialized roots or stems.
What is starch used for in plants?
Long term energy storage.
What are the structural polysaccharides?
Chitin and cellulose.
What is chitin?
A structural polysaccharide that makes up the outer body of insects.
What is cellulose?
It is found in the cell wall of plants and gives them the plants the structure and strength.
What are lipids composed of?
Mostly C and H, fewer O
What is the function of lipids?
Store long term energy, parts of cell membranes–> phospholipids
Three examples of lipids.
Fats, oils, waxes
Composition of fat
1 glycerol, 3 fatty acids
One gram of fat has how much more energy than a gram of carbohydrates?
More than 2x
What can fats not be dissolved in? Why?
Water, because water is polar and the fat is very nonpolar.
What are the two types of fats?
Saturated and unsaturated
What is a saturated fat?
When each carbon in a fatty acid chain has a single bond to the next carbon.
What state of matter is saturated fat usually at room temperature? Give an example.
Solid. Butter.
What does saturated fat tend to do?
Increase the amount of cholesterol found in the body.
What can happen when the cholesterol in the body is increased?
It can narrow the arteries and lead to a heart attack or stroke.
What is an unsaturated fat?
At least one carbon in the fatty acid chain has a double or triple bond to the next carbon.
What state of matter is unsaturated fat usually at room temperature? Give an example.
Liquid, oil
Which is Healthier-saturated or unsaturated fat? Why?
Unsaturated fat because it tends to decrease the amount of cholesterol in the body.
What does unsaturated fat tend to do?
It tends to decrease the amount of cholesterol in the body.
What are proteins composed of?
C, H, O, N
What are proteins made up of?
Joined together amino acids
What are amino acids?
Compounds with a central carbon atom bonded to a H atom, an amino group on one end (-NH2) a carboxyl on the other (-COOH)
What are the different side chains of amino acids called?
An R group.
How many amino acids are found in nature?
Over 20
What are the functions of proteins?
- Help form bone and muscle
- Transport substances into and out of the cell
- Help fight disease
- Allows chemical reactions to take place
What are two proteins found in the body?
Antibodies and enzymes
How can two amino acids be joined together?
Dehydration synthesis.
What is the bond between two amino acids called and what is its nature?
Peptide bond, covalent
What is the resulting molecule of a peptide bond called?
A dipeptide.
What is a long chain of amino acids called?
A polypeptide.
What do polypeptide chains fold together to form?
Proteins.
How many amino acids can proteins have?
Between 50 and 100,000
What shapes can proteins appear in?
A variety, includong coils, pleated sheets, and globules
What are nucleic acids composed of?
C,O,H,N,P
What are nucleic acids formed from?
Individual monomers called nucleotides.
How many parts do nucleotides have? What are they?
- Five carbon sugar, phosphate group (PO4) and nitrogenous base.
What is a nitrogenous base?
A basic molecule that contains nitrogen. It is found in the nucleotide.
What is the function of nucleic acids?
To store and transmit hereditary info
How many types of nucleic acids are there? What are they?
- DNA, or deoxyribonucleic acid, and RNA, or ribonucleic acid.
Where is DNA found? What does it do? How is it shaped?
The nucleus of cells. It codes for proteins, which gives you your traits. Double helix.
What is a double helix?
Twisted ladder shape
What is each side of the double helix a chain of?
Nucleotides.
How are the nucleotides bonded on each side?
Nitrogenous bases make up the rungs of the ladder.
What are the four types of bases in DNA? Which bonds to which?
Adenine, Guanine, Cytosine, and Thymine. Adenine + Thymine and Guanine + Cytosine.
In human cells, how many bases does each DNA molecule have?
3.4 billion
What does ribonucleic acid act as?
A messenger from DNA to ribosomes.
What are ribosomes?
Where proteins are made.
What does RNA consist of?
A single strand of nucleotides.
What sugar does DNA contain?
Deoxyribose
What sugar does RNA contain?
Ribose
What base does RNA have?
Uracil
What do chemical reactions do?
Change one set of chemicals into another sets of chemicals.
What do chemical reactions always involve?
Breaking and/or forming bonds
What are reactants?
Elements or compounds that enter reactions
What are products?
Elements or compounds that are produced by the reaction.
When is energy either released or required?
During chemical reactions.
What classifies a reaction as spontaneous?
If it releases energy.
If A chemical reaction needs to absorb energy in order to occur, it will_____.
Not occur spontaneously.
Do spontaneous reactions require activation energy?
Yes
What is activation energy?
A burst of initial energy that all reactions require to make them start.
What may cause a reaction to occur very slowly?
If the required activation energy is too high and it takes the cell a while to gather the needed energy to start.
What is a catalyst?
A substance that speeds up the reaction by lowering the amount of activation energy needed to start.
What are enzymes?
Protein catalysts found in the cells.
What is the reactant to an enzyme called?
A substrate.
What is the active site?
The place on the enzyme where the substrate can bind.
How many types of substrate does each enzyme fit with? Why?
One, because each enzyme has a different active site.
How do enzymes break bonds or push substrates together? What does this do? What does that result in?
It physically “grabs” the substrate molecules and forces them to react. This creates a place where a reaction can occur which results in the cell needing less activation energy for the reaction.
What is the structure called when an enzyme and substrate are joined?
Enzyme substrate complex.
What happens while the enzyme and substrate or joined?
They react.
What happens when the reaction is done? Can the enzyme be used again?
The products are released. Yes.
How are enzymes very specific?
One enzyme catalyzes one type of reaction.
List 3 enzyme features.
Only enter reaction temporarily, not changed/can be used again and again, usually end in ase and named for what they act on.
Is the enzyme a perfect fit to the substrate? How is it accomodated?
Not necessarily completely. The enzyme slightly changes shape as the substrate enters to accomodate it.
What are the factors by which the rate of the enzyme reaction occurs?
pH values, temperature
What pH do enzymes in most of our body work best at? Where does it function best differently? What number there?
7, stomach, around 2
How does temperature affect the enzyme work rate?
As temp increases, molecules move faster and there is a greater chance of an enzyme meeting a substrate so the rate decreases. They work best at 37C, body temp.
What is denaturing? At what temperature does this usually happen?
The enzyme breaking down. 40C.
What did Robert Hooke look at? What did he describe as cells? What was he really seeing?
Thin slices of cork under a microscope, empty spaces, walls of dead cells.
What did Robert Brown discover? What is that?
The nucleus.the small round central part of the cell.
What did Matthias Schleiden and Theodor Schwann experiment to see? What did they conclude?
Which living things had cells, plants and animals.
What year were schleiden and schwann in?
1838
What year was Hooke in?
1665
What year was Virchow in?
1855
What did Rudolph Virchow study? What did he conclude?
Cell reproduction. Every cell comes from a previous cell.
What is the cell theory?
All living things are made up of one or more cells, cells are the basic unit of structure and function of living things, and all cells come from preexisting cells.
Definition and organisms that are unicellular? Give an example of something unicellular.
Made up of one cell. Bacteria. Ex: paramecium.
Definition and organisms that are multicellular? Give an example of something multicellular.
Made up of many cells. Human.
Why are organisms able to function?
Because their cells are carrying out the necessary functions.
What are the exceptions to cell theory?
Virus, mitochondria and chloroplast, and the first cell.
What is a virus composed of?
A nucleic acid surrounded by a protein covering.
How is a virus not lifelike?
Is nto made out of cells, does not grow or respond to environmental changes, cannot maintain homeostasis.
How is a virus lifelike?
Can reproduce, but only in living cells.
Do we consider a virus to be living?
No.
How are mitochondria and chloroplast lifelike?
They have their own DNA and can replicate themselves.
What is it thought of the origins of mitochondria and chloroplast? What are these called?
That they are the descendants of simple cells, were eaten but not digested by more complex cells Nd eventually became a permanent part of these cells. These are called eukaryotic cells.
What is the exception to the cell theory on the first cell?
It must have risen from non cellular structures.
