Cell Structure Flashcards
1
Q
Metric to metric conversions
A
2
Q
van Leeuwenhoek
A
- First to observe and describe bacteria
- Established that some bacterial cells move
- Viewed human blood, sperm, and pond water with his hand crafted microscopes
- Worked in late 1600s
3
Q
Hooke
A
- Used a microscope to examine a piece of bark
- Called the little structures “cells”
4
Q
Schleiden
A
- Discovered that all plants are made of cells
5
Q
Schwann
A
- Discovered that all animals were made of cells
6
Q
Virchow
A
- Discovered that both plant and animal cells are produced only by division of preexisting cells
- “Every cell from a cell”
7
Q
4 parts to cell theory
A
1) All living things are made of cells. They are the building blocks.
2) Cells are the basic unit of structure and function in living things.
3) All cells come from preexisting cells.
4) Cells contain genes, that serve as the instructions for cell function and growth.
8
Q
Reasons for small cell size: relationship between cell surface area and volume
A
- A cell needs to obtain adequate nutrients and oxygen, dispose of wastes
- Size limited by distance materials must diffuse within a cell
- A small cell has more surface area relative to its cell volume and is more efficient
9
Q
Plasma (Cell) Membrane
A
- Controls passage of materials in and out of the cell
10
Q
Cell Wall
A
- Provides structure and maintains the cell’s shape
- Provides skeletal support, surface protection, and binding of cells in tissues
11
Q
Cytosol
A
- Cytoplasm not including organelles
- Helps move materials within the cell
- Provides support for organelles, gel-like substance
- Gel-like substance
12
Q
Nucleus
A
- Directs the cell’s activities (information center)
- Chromatin (DNA + proteins) which makes up the cell’s chromosomes
- DNA is copied within the nucleus prior to cell division
13
Q
Nucleolus
A
- Produces ribosomes
- Made of RNA + proteins
- Ribosomal RNA is made and assembled with proteins imported from the cytoplasm to make ribosomal subunits
14
Q
Nuclear membrane/envelope
A
- A double membrane with pores that allow material to flow in and out of the nucleus (through nuclear pores)
- It is attached to the ER
15
Q
Ribosomes
A
- Protein synthesis
- Synthesized in the nucleolus
- Free ribosomes are suspended in the cytoplasm
- Bound ribosomes are attached to the ER or the nuclear envelope
16
Q
Smooth ER (ex)
A
- Lacks attached ribosomes
- Can store enzymes
- Synthesis of lipids (oils, phospholipids, steroids)
- Cells of ovaries (synthesize steroid sex hormones)
- Liver cells (enzymes help process harmful substances)
- Storage of calcium ions (muscle cells)
- Near nucleus
17
Q
Rough ER (ex)
A
- Modifies/edits proteins made by ribosomes
- Makes additional membrane for itself and proteins destined for secretion
- Once proteins are synthesized, they are transported in vesicles to other parts of the endomembrane system
- Common in cells that make a lot of proteins:
- White blood cells
- Pancreatic cells
22
Q
Mitochondria
A
- Carry out cellular respiration in most euk. cells
- Chemical energy of foods (sugar) → ATP
- Enclosed by 2 membranes
- Intermembrane space — narrow region between 2 membranes
- Mitochondrial matrix — contains materials necessary for ATP generation (DNA, ribosomes, enzymes)
- Inner membrane highly folded, protein molecules that make ATP embedded in it
- Divides by itself when cell divides
23
Q
Chloroplast
A
- The photosynthesizing organelles of plants (and some protists)
- Light energy → chemical energy of sugar molecules
- Inner and other membrane
- Chlorophyll pigment
- Has its own DNA
- Stroma – thick fluid containing DNA, ribosomes, and enzymes
- Thylakoids – network of interconnected sacs
- Grana – stacks of thylakoids, sites where the green chlorophyll molecules embedded in their membranes trap solar energy
27
Q
Microfilaments
A
- Long thin actin protein fibers
- Aid in cytoplasmic streaming (movement of cytoplasm)
- Muscle contraction
