Midterm Flashcards
Lecture 2 ~ 8
2
Biology
Definition
Biology: science that studies life
2
6 Properties of Living Things
List them (probably with examples)
- Order
- Maintaining stable internal environment (homeostasis)
- Respond to external stimuli
- Positive response: Movement toward a stimulus
- Negative response: Movement away from a stimulus - Growth
- Reproduction
- Energy processing
2
What about viruses?
Are they alive?
- Most biologists think viruses arem’t alive
- But they are biological
2
The earliest observation of cells
3 stages(?) steps(?)
Leeuwenhoek: made good quality lens (not for cells though) and it became microscopes.
Robert Hooke: Observed cell walls under a microschope
Schleiden & Schwann: Oberserved cells and came up with cell theory
2
Cell Theory
List the 3 parts
- All organisms are made out of one or more cells.
- Cells are the basic structural & functional unit of all living organisms.
- All cells come from pre-existing cells.
2
Theory v.s. Hypothesis
Define them
Hypothesis: a testable/falsifiable predictions that attempts to explain an observation/phonomenon.
Theory: a general set of ideas that is intended to explain facts or events. (Evidence collected from hypothesis support theory.)
이거 또 틀리기만 해봐라
2
The Process of Science
(I don’t think it’s gonna be tested though) but there is 5 steps
- Make an observation
- Ask a question
- Form a hypothesis
- Make a prediction
- Test the prediction
(If it’s not testable… go back to 1 and just make more observation)
2
Where does the energy used to sustain the biosphere come ultimately come from?
Here comes the
SUN
2
Where energies are stored & how energies are earned/used
Where are energies stored? How plants/animals process energy?
Energy in living things are stored as chemical energy.
- Energy is stored in the bonds between the atoms of molecules.
For plants/photosynthetic organisms, light energy is converted to chemical bonds to put sugar (glucose) together.
For the living things that can’t do photosynthesis, they nom nom food/molecules to get energy.
2
Autotrophs
Heterotrophs
Define them
Authotrophs: Use abiotic sources of energy to produce complex molecules.
ex) Plants using light
Heterotrophs: MUST use the complex molecules produced by autotrophs* as an energy source
ex) Humans
3
Metabolic pathways
There is 2. Energy required? or energy released?
Anabolic: Small molecules are built into large ones
-> Energy required
Catabolic: Large molecules are broken down into small ones
-> Energy released
3
4 Types of chemical bonds
- Ionic bonds: When the elements donates & accepts electrons to each other.
- Covalent bonds: electrons are shared between atoms to form a strong association.
- Nonpolar covalent bond: all the atoms share the electrons equally.
- Polar covalent bond: The electrons shared spend more time closer to 1 nucleus to the other one. It results slightly (+) & (-) charged atoms.
3. Hydrogen Bonds (polar covalent): form between H atoms and other polar covalent molecules.
- Unique properties of water & DNA/proteins - Van der Waals Interaction: weak interactions between molecules that occur between polar covalently bound atoms in different molecules.
3
Why is carbon so important in living things?
C can bond with up to 4 other atoms to form diverse molecules with elabroate structures.
3
Organic compounds & carbon fixation
Define. Alsom what are the exceptions?
Organic compounds: carbon containing compounds.
- CARBON BONDED TO OTHER C OR H
- CO & CO2 ARE NOT ORGANIC!!!
Carbon fixation: conversion from inorganic compound -> organic molecules useful for living things
- It takes a lot of energy to do it
3
4 Major Organic Compounds
Just list them cuz they will each have their own separate slide.
- Lipids
- Carbohydrate
- Nucleic Acids
- Proteins
3
Lipids
Describe.
- FATS (fats, oils, waxes, steroids)
- Important energy source
- Long chains of C & H
- The C&H chains are neutral in charge
- Hydrophobic (cuz they’re non-polar)
- Only the small portion at the end with the only Oxygen can interact with water.
- Builds hormones
- Lipids in water arranges themselves in a way to “shield” the hydrphobic portions away from water
- Phospholipids: form the basis of biological membranes (helps maintain the stable internal envrionment)
얘네 organic compounds 4개 중에 유일하게 hydrophobic
3
Carbohydrates
- SUGAR
- Provides energy to our body
- Monosaccharides: simple sugars (glucose)
- > this one is a monomer
- Major ones have 6 carbon atoms
- Hydrophilic! (cuz sugar dissolves in water lmao)
3 - 4
Nucleic Acids
- Polymers of nucleotide
- It stores genetic info in cells.
- DNA&RNA
- There are 5 kinds of nucleotides and each nucleic acid contains 4 of them (A,C,T,G,U)
Structure: - Base: determines what kind of nucleotide it is (The only differences between different types of nucleotide is the base).
- Nucleoside: Sugar + base
- Nucleotide: sugar + base + 1~3 phosphates
nucleotide가 nucleic acid 되려면 4개 필요
4
DNA vs RNA
- Sugar is different
- RNA = Ribose, DNA = Deoxyribose
- This extra oxygen in DNA makes it more stable than RNA
- RNA is less stable but breaks down much quicker - Types of nucleotides
- RNA: U, DNA: T
4
Base pairing & DNA structure
and what bonds
- Each nucleotide specifically pairs with another by forming HYDROGEN BOND
- The # of bonds affects the trength of interaction, 즉, G & C가 부수기 더 어려움.
- New nucleotides are added at 3’ end, forming COVALENT BOND
- The complementary strand runs in the opposite direction (만약 5->3이면 3->5)
same strend = covalent
different strend = hydrogen
makes sense because 다른 strend는 어차피 나눠질거 그렇게 strong한 bond가 아니어도 상관없음
4
Base pairing & RNA structure
- RNAs can fold in different ways that perform specific functions.
- The sequence of nucleotides determines RNA molecule’s structure.
4
ATP
Define & 3 steps of how it is used as energy
ATP: transfers energy from broken down sugars amd fats to various cellular functions.
- It has 3 phosphates.
1. The last phosphate is removed and gets transferred to whatever function it needs
(ATP becomes ADP + phosphate)
2. We nom nom food and that energy gets digested and broken down.
3. That digested energy is used to put ADP and phosphate back together to ATP!
(and then over and over again)
3 - 4
Proteins & Amino acids
Define. Describe characteristics (그냥 생각나는 대로 막 뱉어)
- Amino acids: fundamental unit that make up proteins
- Peptides: short chains of amino acids (<30)
- Protein: Polymers of amino acids
- Most diverse in function in the cell
- About 20 kinds of relevant amino acids in real life.
- Each amino acid monomer has a unique “side chain”
4
How amino acids join
what bond?
- They form a covalent bond
- Also have directionality (new amino acids will be added to the c-terminus)